Abstract:
The shared user interface surface system is a simple and lightweight collaboration tool that is accessible simultaneously by multiple users through multiple sources. The shared user interface surface system provides a way to share a user interface surface and corresponding shared surface object, and coordinates local manipulations of respective local representations of the shared user interface surface and corresponding shared surface object, and updates the respective local representations with a group representation. The system accommodates diverse collaboration requirements including mixed written and spoken languages, utilization of the accessibility layer for physically disabled and disparate computing resources.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    This disclosure concerns a collaboration tool that is accessible simultaneously by multiple users through multiple sources. In particular, this disclosure concerns a system, product and method for sharing a user interface surface and corresponding shared surface object that coordinates local manipulations of respective local representations of the user interface surface and corresponding shared surface object, and updates the respective local representations with a group representation. 
         [0003]    2. Related Art 
         [0004]    Organizations are continually challenged to identify efficient and cost effective collaboration tools. Today, members of globally distributed organizations increasingly collaborate with other members from different regions of the world. Unfortunately, rising fuel costs and the time required to travel in order to collocate individuals create barriers to improving the economic positions of many organizations. Unfortunately, organizations without collaboration tools that are simple, lightweight and provide a high performance way to share a user interface surface among multiple users may, as a result, also fail to realize the productivity gains necessary to be competitive. 
         [0005]    The fast pace of many industries require organizations to rapidly assemble teams from various areas of expertise that can quickly identify problems and develop solutions. Organizations with globally distributed workforces who work under compressed development schedules in highly specialized and complex knowledge areas need a tool that reduces barriers to collaboration. Regardless of the geographical distribution of an organization, members of organizations may have diverse collaboration requirements (e.g., varying languages, physical disabilities and computing resources) that many collaboration tools may not even accommodate. 
         [0006]    Currently available collaboration tools are generally restricted in one of three ways: 1) a physical location defines where a collaboration may take place (e.g., Thunder® and TeamSpot®); 2) a session defines the availability and existence of shared content so that once the session ends the shared content becomes unavailable (e.g., WebEx and Adobe Connect®); and 3) a user owns a document, the user grants and revokes rights to the document, and the document is stored on the owner&#39;s resources where documents are shared over a network (e.g., Microsoft OneNote®). 
         [0007]    Collaboration tools that are highly customized and expensive to implement may impose user-side computing requirements (e.g., resource intensive client-side systems) and require significant user training. For example, Sharepoint® documents are serially checked-out and edited from a common repository. Some group-collaboration tools adhere to strictly linear text formats (e.g., SubEthaEdit® and Google Docs®). Collaborative tools such as skrbl.com®, thinkature.com®, conceptShare® and Adobe JamJar® are based on small text snippets, but limit the type of content available for sharing. Collaboration tools often may use elaborate schemes in order to maintain versioning information for each collaborator and require significant system administration support in order to properly maintain. Such collaboration tools may also limit the type of information and data with which users can collaborate. 
       SUMMARY 
       [0008]    The shared user interface surface system (hereinafter “system”) provides a cost effective and lightweight collaboration tool that multiple users can simultaneously access through multiple sources. The system provides a persistent shared user interface surface that is synchronized in real-time with all users accessing the shared user interface surface. A shared user interface surface (e.g., canvas) may include various types of content (e.g., text items, sketches and images). A shared user interface surface may be used as a scratch pad for a single user and/or as a shared space for multiple users, because shared user interface surfaces are stored on a web server rather than being stored on the hard drive of a particular user. Accordingly, shared user interface surface can be viewed, edited and shared by multiple users from various locations, simultaneously. 
         [0009]    In one implementation, the system provides a way to share a user interface surface that is accessible simultaneously by multiple users through multiple respective sources. The system may comprise a processor and memory coupled to the processor. The memory may comprise shared surface logic that generates local canvases that are responsive to user interactions. The local canvases include a first local canvas and a second local canvas, and each local canvas comprises local canvas boundaries and a local canvas identifier. The shared surface logic may also generate a first group canvas that corresponds to at least two of the local canvases. The local canvases corresponding to the first group canvas establish a first set of local canvases that are respective local representations of the first group canvas. The first group canvas is a shared surface representation of the first set of local canvases. The memory may further comprise interaction detection logic that detects multiple user interactions corresponding to the local canvases. One of the detected multiple user interactions may correspond to the first set of local canvases. The interaction detection logic may update the first group canvas to obtain an updated first group canvas, and update the first set of local canvases based on the updated first group canvas. 
         [0010]    Other systems, methods, features and advantages will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. All such additional systems, methods, features and advantages are included within this description, are within the scope of the claimed subject matter, and are protected by the following claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The system may be better understood with reference to the following drawings and description. The elements in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the system. In the figures, like-referenced numerals designate corresponding parts throughout the different views. 
           [0012]      FIG. 1  illustrates a shared user interface surface system architecture. 
           [0013]      FIG. 2  shows a user interface surface system. 
           [0014]      FIG. 3  shows user interface modes. 
           [0015]      FIG. 4  shows shared surface object metadata. 
           [0016]      FIG. 5  shows a group canvas shared surface object record. 
           [0017]      FIG. 6   a  shows correlations between shared surface objects, group canvases, group canvas shared surface object representations, local canvases and local canvas shared surface object representations. 
           [0018]      FIG. 6   b  shows a first graphical display area with multiple local canvases corresponding to multiple group canvases. 
           [0019]      FIG. 6   c  shows a second graphical display area with a local canvas corresponding to a group canvas. 
           [0020]      FIG. 6   d  shows a third graphical display area with multiple local canvases corresponding to multiple group canvases. 
           [0021]      FIG. 7  illustrates graphical display area components of a graphical display area. 
           [0022]      FIG. 8  illustrates a local canvas shared surface object representation over an elapsed time period during which no local canvas manipulation occurs. 
           [0023]      FIG. 9  shows the logic flow the shared user interface surface system may take to update a local canvas shared surface object representation. 
           [0024]      FIG. 10  shows the logic flow the shared user interface surface system may take to apply local canvas shared surface object presentation preferences. 
           [0025]      FIG. 11  illustrates a local canvas comprising multiple local canvas shared surface object representations. 
           [0026]      FIG. 12  illustrates a local canvas comprising a semi-transparent annotation layer overlaying local canvas shared surface object representations. 
           [0027]      FIG. 13  shows local canvases of varying sizes set to different user interaction modes. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    The system provides a simple, lightweight, and high performance way to share a user interface surface among multiple users through multiple sources. In one implementation, the system employs client-server architecture that includes Ruby on Rails® on the server-side and Microsoft .Net libraries to deploy client-side applications running on Windows platforms, including Windows XP and Vista. The system may employ alternative technologies such as ASP.NET and server-side Java to create web services, and/or server-side frameworks such as Django® and Lift®. In one implementation, the client-side applications (e.g., web page showing a RSS feed running on a mobile device) may be written using Java, C++, and/or any other client-side technology. In one implementation, the system resembles a drawing program and/or a digital whiteboard that produces a semi-structured document (e.g., canvas) similar in appearance to a Microsoft OneNote page. The system may employ the representation state transfer (REST) software application architecture that is modeled after the way data is represented, accessed and modified on the web. The system considers data and functionality to be resources that are accessible using Uniform Resource Identifiers (URIs) (e.g., links on the Internet). The system employs RESTful web services that use a standardized interface (e.g., XML files) and stateless communication protocol (e.g., HTTP) to exchange representations of resources between clients and servers. 
         [0029]    Local canvases and local canvas shared surface object representations may correspond to client-side resources, while group canvases and group canvas shared surface object representations correspond to server-side resources. A local canvas may display the local canvas state of a shared surface object, communicate local canvas user interactions to the system, poll the system for the group canvas state of the shared surface object, and fetch and update the local canvas with the group canvas state of the shared surface object. A local canvas may be used as a standalone executable program and/or as a Rich Internet Application. A local canvas may be maintained continuously, minimized and left running in the background. Drawing and sketching capabilities using a local canvas may be supported by the addition of a stylus on a Tablet PC and/or with outboard tablet hardware. 
         [0030]    In one implementation, the system comprises web applications that expose resources (e.g., data and functionality) through web URIs and use HTTP methods (e.g., GET, POST, PUT and DELETE) to create, retrieve, update and delete resources. The function calls may be in the form of http://servername/admin/functionname. In one implementation, the method calls used by the system include credentials in the HTTP header that are authenticated against an extended security option (ESO) web service. 
         [0031]    The HTTP GET method may use the local canvas identifier to request a resource. HTTP GET with specially formatted URL may return a list of shared surface objects in the local canvas identified by the local canvas identifier and information about the shared surface object, including: the shared surface object identifier and the group canvas shared surface object version. The HTTP POST method call may create a resource, including images, drawings, and other binary-based content. The HTTP POST method call may include a field encoded into a text format compatible with URL encoding and storage in a database (e.g., MySql database and/or other databases compatible with Ruby on Rails®). The HTTP PUT method call modifies a resource identified by a local canvas identifier. 
         [0032]    A local canvas may compare the local canvas shared surface object version to the group canvas shared surface object version to determine whether to update the local canvas shared surface object representation with the group canvas shared surface object representation. In one implementation, in the event a local canvas communicates a non-universally unique local canvas identifier, shared surface object identifier, group canvas shared surface object version and/or local canvas shared surface object version to the system, the system returns an ‘unknown/undefined’ value as a consequence. 
         [0033]    Multiple simultaneous local canvas user interactions may occur corresponding to different local canvases, referred to as the collision scenario. In one implementation, the system determines whether an update of a local canvas shared surface object representation is “stale”. The system may consider an attempt to update a local canvas shared surface object representation that does not correspond to the group canvas shared surface object version to be stale. In other words, a local canvas shared surface object version that is earlier than a corresponding group canvas shared surface object version is considered stale. 
         [0034]    For example, a first user and a second user, through different local canvases corresponding to a common group canvas, simultaneously perform local canvas user interactions, a first local canvas user interaction and a second local canvas user interaction, respectively. The system determines the first local canvas user interaction to be received first and accepted, the group canvas shared surface object version is updated, the group canvas shared surface object representation is updated with the first local canvas shared surface object representation. The system determines the second canvas user interaction to be received second and declared stale. The second local canvas user interaction may be discarded. In one implementation, the second local canvas user interaction is stored for use by the second user. The second local canvas may discover the collision by polling the system for the state of the local canvas shared surface object representation and determine that the local canvas shared surface object representation is stale. For example, the second local canvas may compare the local canvas shared surface object version and group canvas shared surface object version, and determine that the group canvas shared surface object version is more recent. The second local canvas may fetch the group canvas shared surface object representation to update the local canvas shared surface object representation and local canvas shared surface object version. 
         [0035]    When a shared surface object is added to a local canvas (e.g., a user adds a file and/or other content to the local canvas) the local canvas shared surface object representation of the local canvas shared surface object may be displayed directly in the local canvas (e.g., text or images). A service provider responsive to the local canvas shared surface object may be employed to present the local canvas shared surface object representation of the local canvas shared surface object in the local canvas. For example, the shared surface object may be an audio clip and when the shared surface object is added to the local canvas an audio player and/or editor (e.g., service provider) is enlisted to present the local canvas shared surface object representation in the local canvas. 
         [0036]    In the event the local canvas cannot display the local canvas shared surface object representation (e.g., a service provide is unavailable to the local canvas to present the local canvas shared surface object representation), the local canvas shared surface object may be represented in the local canvas as a stub (e.g., a hyperlink reference to the local canvas shared surface object. A local canvas shared surface object corresponding to a stub may be stored in a shared documents folder of the local canvas user (e.g., SharePoint site) and the stub points to location of the local canvas shared surface object in the shared documents folder. When group canvas users select the stub in the respective local canvases, the local canvas shared surface object loads directly from the shared documents folder. 
         [0037]      FIG. 1  illustrates a shared user interface surface system architecture (hereinafter “architecture”)  100 . The architecture  100  includes the shared user interface surface system (hereinafter the “system”)  102 , multiple users  104 , a shared surface object repository  106 , service providers  108 , graphical displays  110 , and non-display peripherals  112 . The components of the system architecture  100  may communicate with each other through networks  114  (e.g., the Internet). 
         [0038]    The system  102  may generate group canvases (e.g., a first group canvas  116 , a second group canvas  118  and third group canvas  120 ). A group canvas (e.g.,  116 ,  118  and  120 ) represents a shared representation of a shared surface corresponding to a local representation of the shared surface represented by a local canvas (e.g., first local canvas  122 , a second local canvas  124  and a third local canvas  126 ). In other words, the multiple users  104  access local representations of a shared surface through local canvases, while a group representation represents a synchronized version of the shared surface and corresponds to a group canvas. From time to time local canvases may include user interactions from the multiple users  104  that have not been synchronized, and differences between local canvases and corresponding group canvas reflect such user interactions. 
         [0039]    The non-display peripherals  112  may include various non-visual communication devices, including: speakers; microphones; touch pads; and malleable surfaces (e.g., used for brail or to replicate terrain). The non-display peripherals  112  may utilize the Microsoft accessibility layer functionality and augment and/or substitute for the capabilities provided by the graphical displays  110 . In one implementation, the system  102  employs the service providers  108  and non-display peripherals  112  to provide non-visual representations of local canvases and local canvas shared surface object representations, and allow users to non-visually manipulate the local canvases and local canvas shared surface object representations. For example, a user may communicate audio commands through a microphone (non-display peripheral  112 ) to manipulate a local canvas and/or local canvas shared surface object representation. 
         [0040]      FIG. 11  illustrates a local canvas comprising multiple local canvas shared surface object representations  1100 . Local canvas shared surface object representations (e.g.,  1102 ,  1104 ,  1106 ,  1108 ,  1110 ,  1112 ,  1114  and  1116 ) may vary in size and content, and comprise any number of unique characteristics. A local canvas may comprise a local canvas side-bar  1118  that includes local canvas tools  1120 . Inactive local canvas shared surface object representations and icons and/or avatars of group canvas users (e.g., a buddy list) may be positioned in the local canvas side-bar  1118 . A user may create in a first local canvas a short-cut to a second local canvas so that the user can quickly move between canvases. 
         [0041]    In one implementation, the system  102  generates a number of persistent group canvases (e.g., 100,000 group canvases) the number of which an administrator may pre-configure and periodically generate as needed. A user may browse the group canvases and select a particular group canvas to use. A user may use the local canvas tools  1120  to invoke a ‘get next available canvas’ selection that locates an unused group canvas. 
         [0042]      FIG. 2  illustrates a detailed embodiment  200  of the shared user interface surface system  102 . The system  102  includes a communications interface  202  that the system  102  uses to communicate with the various components through the networks  114 , a processor  204  and a memory  206 . The memory  206  may includes shared surface logic  208 , interaction detection logic  210  and service provider logic  212 . In one implementation, the shared surface logic  208 , interaction detection logic  210  and service provider logic  212  correspond to web services that exchange representations of shared surface object representations between local canvases and group canvases. 
         [0043]    The shared surface logic  208  may generate local canvases (e.g.,  122 ,  124  and  126 ) responsive to user interactions from the multiple users  104 . A local canvas comprises local canvas boundaries (e.g., first LC boundaries  214 ) that define the dimensions of the local canvas and a local canvas identifier (e.g., first LC identifier  216 ) that uniquely identifies the local canvas. A local canvas identifier  216  corresponds to a graphical display area  218  identified by a graphical display identifier  220 . 
         [0044]    The shared surface logic  208  may generate group canvases (e.g.,  116 ,  118  and  120 ). A group canvas (e.g.,  116 ,  118  and  120 ) represents a shared representation of a shared surface. A group canvas (e.g.,  116 ,  118  and  120 ) includes a group canvas identifier (e.g., first GC identifier  222 ), and group canvas boundaries (e.g., first GC boundaries  224 ) that define the dimensions of the group canvas. A local canvas may correspond to more than one group canvas. For example, the shared surface logic  208  may generate the first group canvas  116  and the second group canvas  118  corresponding to a first and a second set of local canvases, respectively, from the local canvases (e.g.,  122 ,  124  and  126 ) so that the first set of local canvases include  122  and  124  and correspond to the first group canvas  116 , while the second set of local canvases include  122  and  126  and correspond to the second group canvas. In the aforementioned example, the first local canvas  122  corresponds to two group canvases (e.g.,  116  and  118 ). 
         [0045]    A first local canvas  122  and a second local canvas  124  that comprise first local canvas boundaries and second local canvas boundaries (e.g.  214 ), respectively, where at least a portion of the first local canvas boundaries and second local canvas boundaries are common to both the first local canvas and the second local canvas may define a group canvas (e.g.,  116 ) comprising group canvas boundaries (e.g.,  224 ) corresponding to the portion of the first local canvas boundaries and the second local canvas boundaries that are common to both local canvases. 
         [0046]    A first local canvas  122  and second local canvas  124  that comprise first local canvas boundaries and second local canvas boundaries where the first local canvas boundaries are within the second local canvas boundaries may define a group canvas comprising group canvas boundaries corresponding to the first local canvas boundaries. A local canvas may comprise local canvas boundaries where at least two different portions of the local canvas boundaries correspond to two different group canvases. 
         [0047]    A first group canvas  116  and second group canvas  118  may comprise first group canvas boundaries and second group canvas boundaries where the first group canvas boundaries and the second group canvas boundaries define a third group canvas  120  where the first group canvas boundaries and the second group canvas boundaries are within the third group canvas boundaries. 
         [0048]    The local canvases (e.g.,  122 ,  124  and  126 ) and group canvases may each include a user interaction (UI) mode specifier (e.g., first LC UI mode  226  and first GC UI mode  228 , respectively) that specifies the types of interactions to which the corresponding local and group canvases may be responsive. The local canvas UI mode (e.g., first LC UI mode  226 ) may be user configurable (discussed further below). The group canvas UI mode (e.g., first GC UI mode  228 ) may be configurable by an administrator, the  102  system, and/or at least one of the multiple users  104  designated with the authorization to set the group canvas UI mode (discussed further below). 
         [0049]    The system  102  includes a group canvas user status  260  and group canvas user identifier  262  for each group canvas to which each of the multiple users  104  correspond. The group canvas user status  260  indicates the state of a user of a local canvas corresponding to a group canvas. For example, the group canvas user status  260  indicates whether a user is currently interacting with a corresponding local canvas, whether the user is available to interact with the local canvas, and whether the user has recently interacted with the local canvas. The group canvas user identifier  262  uniquely identifies a local canvas user corresponding to a group canvas. 
         [0050]    The interaction detection logic  210  may detect the user interaction modes  230  (e.g.,  226  and  228 ), the group canvas user status  260  and the group canvas user identifier  262  to determine the level of collaboration and interaction available between the multiple users  104 . The system  102  may use the group canvas user status  260  and the group canvas user identifier  262  to present an icon and/or avatar corresponding to a user for each of the respective group canvases to which a user corresponds. 
         [0051]    Local canvases (e.g.,  122 ,  124  and  126 ) may include a local canvas shared surface object representation (e.g., first LC shared surface objects representations  232 ). Group canvases (e.g.,  116 ,  118  and  120 ) may include group canvas shared surface object representation to which respective local canvas shared surface object representations correspond. The system  102  may synchronize a local representation with a corresponding group canvas shared surface object representation based on the user interaction modes  230  (e.g.,  226  and  228 ), the group canvas user status  260  and the group canvas user identifier  262 . 
         [0052]    The multiple user interactions  234  may represent respective local manipulations (e.g., first LC manipulations  236  and second LC manipulations  238 ) of a local canvas shared surface object representation  232 , wherein at least a portion of the local canvas shared surface object representation  232  is within the local canvas boundaries of a corresponding local canvas. The interaction detection logic  210  may detect the local canvas shared surface object representation  232  using a shared surface object identifier  240 . The interaction detection logic  210  may detect the multiple user interactions  234  corresponding to the local canvases (e.g.,  122 ,  124  and  126 ), detect whether at least two of the multiple user interactions  234  correspond to one of the local canvases and whether the multiple user interactions  234  correspond to at least two different users of the multiple users  104 . For example, where at least two of the multiple users  104  simultaneously interact with the first local canvas  122 , the interaction detection logic  210  can detect whether the simultaneous interactions with the first local canvas  122  represent interactions from separate users. 
         [0053]    The service provider logic  212  may analyze shared surface object metadata  242  corresponding to the local canvas shared surface object representation  232 . The service provider logic  212  may communicate the shared surface object metadata  242  and the local manipulations of the local canvas shared surface object representations  244  to service providers  108  responsive to the local canvas shared surface object representation  232  and shared surface object metadata  242 . The service providers  108  generate updates of the local canvas shared surface object representation  246  for each of the local canvases corresponding to the respective local manipulations of the local canvas shared surface object representations  244 . The updates of the local canvas shared surface object representation  246  may be different for each local canvas (e.g.,  122 ,  124  and  126 ) until the local canvases are synchronized with an updated group canvas shared surface object representation. For example, a service provider  108  that provides a videoconferencing service may fetch the contents of a videoconference window from a web server and rendered the content in a local canvas using a web browser component. The system  102  may orchestrate the collaboration of services provided by service providers  108 . In one implementation, the system  102  is representation neutral so that a local canvas can be presented in any number for formats. For example, a local canvas may be represented in a list format such as provided by a RSS feed. 
         [0054]    The interaction detection logic  210  may generate a group canvas shared surface object record  248 , based on the shared surface object metadata  242  and the updates of the local canvas shared surface object representation  246  received from the service provides  108 . The interaction detection logic  210  may store the group canvas shared surface object record  248  in the shared surface object repository  106 . The interaction detection logic  210  may update each of the local canvases (e.g.,  122 ,  124  and  126 ) with the update of the local canvas share surface object representations  246  and the respective update of the local canvas (e.g.,  250 ). In other words, in one implementation, the interaction detection logic  210  updates a local canvas share surface object representation with updates that result from local manipulations  236  before updating the local canvas share surface object representation with a corresponding update of the group canvas share surface object representation. The interaction detection logic  210  may retrieve the group canvas shared surface object record  248  from the shared surface object repository  106 , using the shared surface object identifier (e.g.,  216 ), and update the local canvas shared surface object representation  246  using the group canvas shared surface object record  248 . 
         [0055]      FIG. 3  illustrates user interaction (UI) modes  230  of the system  102 . The user interaction modes  230  include local canvas UI modes (e.g., first LC UI mode  226 ) and group canvas UI modes (e.g., first GC UI mode  228 ). The local canvas UI mode (e.g.,  226 ) may be user configurable. The group canvas UI mode (e.g.,  228 ) may be configurable by an administrator, the  102  system, and/or at least one of the multiple users  104  with the authorization to set the group canvas UI mode. The user interaction modes for both the local canvas UI modes and group canvas UI modes include a gadget mode  302 , a local annotation mode  304 , a group annotation mode  306 , passive mode  308  and communication modes  310 . One or more of the user interaction modes  230  may be concurrently specified in order to configure a local canvas and/or group canvas. 
         [0056]    Referring briefly to  FIG. 13 , local canvases of varying sizes set to different user interaction modes  1300  are shown. Local canvases may be used in a variety of settings, sizes and user interaction modes, including: a miniature size  1302 , as a desktop computer gadget or widget; the display size of a computer  1304 , suitable for direct viewing and interaction by a local canvas user; a large size  1306  (e.g., on a projected surface in a meeting room), in a passive read-only mode for group visibility; and large size in an interactive mode on a digital whiteboard or a touchable interactive wall. A local canvas may be scaled up with the use of digital whiteboards, touch displays, and/or large interactive walls. A local canvas may be used with an interactive wall for a user that desires to review existing contents, arrange the content and/or sketch over the content. 
         [0057]    Returning to  FIG. 3 , the gadget mode  302  may provide an awareness function that indicates the mode of each of the local canvases corresponding to a group canvas. The awareness function of the gadget mode  302  may also allow the system  102  to present the group user status  260  and group user identifier  262  of each group canvas user to which the local canvas corresponds (e.g., a buddy list in messaging program). The system  102  may use the awareness function information of the gadget mode  302  to present an icon and/or avatar that indicates the local canvas UI mode (e.g.,  226 ), the group canvas user status  260  and the group canvas user identifier  262  to which a local canvas user corresponds. In one implementation, a local canvas user may disable the gadget mode  302  of the local canvas user so that the local canvas user may interact with the local canvas in a cloaked mode and corresponding group canvas users cannot discover the group user status  260  and group user identifier  262  of the local canvas user. In one implementation, the gadget mode  302  may present a local canvas in a miniature size, with a reduced amount of visual detail, at the edge of the screen. When group canvas users modify a group canvas share surface object representation, a visual indicator may appear across the gadget and then slowly fade over time, so that the gadget makes the local canvas user peripherally aware of the share surface object. 
         [0058]    Referring briefly to  FIG. 12 , a local canvas comprising a semi-transparent annotation layer overlaying local canvas shared surface object representations  1200  is shown. The system may employ a semi-transparent annotation ‘layer’ (e.g.,  1202 ,  1204  and  1206 ) to overlay a local canvas shared surface object representation with local and/or group annotations, allowing for non-destructive highlighting, commentary, annotation and markup. Returning to  FIG. 3 , the local annotation mode  304  may allow updates of a local canvas and local canvas shared surface object representation, in response to a respective local canvas user interaction with the local canvas, while preventing the local canvas user interaction to be used to update a corresponding group canvas. In other words, the local annotation mode  304  may allow local canvas interactions to be limited to the corresponding local canvas. For example, under the local annotation mode  304  a local canvas interaction corresponding to a first local canvas is used to update the first local canvas, but the system  102  does not use the local canvas interaction to update a second local canvas that corresponds to a group canvas that the first local canvas also corresponds. The system  102  may allow a user to store local annotations separately from group annotations so that local canvas and group canvas annotations can be maintained. 
         [0059]    The group annotation mode  306  may allow updates of the local canvases corresponding to a group canvas, in response to a local canvas user interaction with at least one of the local canvases corresponding to the group canvas. The group annotation mode  306  may represent the most collaborative of the user interactive modes  230 . In one implementation, the group annotation mode  306  may allow a local canvas user to specify a group canvas user from which the local canvas user will accept and/or exclude interactions, based on the authority and/or role of the local canvas user. 
         [0060]    The passive mode  308  may set a local canvas to read-only to prevent updates of a local representation in response to a local canvas user interaction with the local canvas. The passive mode  308  may not prevent updates of the local canvas with a corresponding group canvas representation. In one implementation, the system  102  may use the passive mode  308  as a default for local canvases that do not have local canvas user interaction capabilities. For example, a local canvas may be presented in a graphical display area of a kiosk that does not provide local canvas user interaction capabilities. In another example, a local canvas may be set to passive mode  308  and displayed on a physically large screen (e.g., wall) for a group of people to occasionally use for a meeting and/or brainstorming session and/or continuously use as a shared group display and/or bulletin board. 
         [0061]    In one implementation, a group canvas may be accessed using a machine-consumable web service and/or RSS feed (e.g., really simple syndication) using an RSS reader (e.g., iGoogle® and Google Reader®). A user interaction with a shared surface object may trigger the creation of an event, task and/or email. A web service (e.g., service provider) may be configured with a watch list of user interactions that trigger the initiate events, tasks and/or emails. For example, a group canvas may be monitored for interactions that correspond to a particular subject and/or manipulation of a particular shared surface object. The user interaction may represent and/or result in the creation of an assignment and/or completion of a task by a user and/or group of users. A task and status of the task may be communicated simultaneously to multiple applications used to track the progress of tasks (e.g., Microsoft Project®, Outlook Tasks®, and/or a Calendar) so that the system may be used to impose a workflow. For example, a canvas user may create a text snippet and designate the text snippet a task corresponding to a workflow of an organization, assign the task and send the task to the assignee. The task becomes a task item on the canvas and reflects the status (e.g., in-progress, unassigned, and complete). A service provider may monitor task tracking applications for completion of a task and communicate the status of the task to a corresponding group canvas. 
         [0062]    The communication mode  310  allows each local canvas user to specify one or more preferred methods of communication to use when communicating with group canvas users corresponding to a group canvas that the local canvas user corresponds. The communication mode  310  may include any combination of communication methods, including: text; multimedia web cam; audio; and e-mail. In one implementation, local canvases comprise built-in audio conference and/or video conference links so that a corresponding local canvas user may communicate with corresponding group canvas users (e.g., connecting to a ‘party line’). 
         [0063]    The system  102  evaluates the communication mode  310  of a local canvas user and a group canvas user to determine the one or more communication methods available for communications between the local canvas user and the group canvas user. For example, a local canvas user may set the communication mode  310  to indicate a particular written and/or spoken language that is different from the written and/or spoken language indicated by the group canvas user. The system  102  may translate content between to two languages so that the local canvas user and the group canvas user can communicate. Similarly, a local canvas user may set the communication mode  310  to indicate that a non-display peripheral be used because the user is visually impaired. 
         [0064]    For example, a group canvas user may specify audio as the communication mode  310 , while the local canvas user may specify text as the communication mode  310 . The local canvas user may select the icon and/or avatar corresponding to the group canvas user to which the local canvas user corresponds to initiate communication with the group canvas user. The system  102  evaluates the communication modes  310  and when the local canvas user originates a text message to the group canvas user the system  102  translates the text message into an audio message for the group canvas user, and when the group canvas user originates an audio message (e.g., response or reply) the system translates the audio message into a text message. 
         [0065]    The system  102  may evaluate each of the communication modes  310  specified by the local canvas user and group canvas user, respectively, and determine a combination of communication methods provide the best communication method. For example, although a local canvas user and group canvas user both specify multimedia web cam as the communication mode  310 , the system  102  may determine the multimedia web cam quality of service unreliable and to ensure that the local canvas user and group canvas user receive the communications between the two use text and/or e-mail messaging to send a written transcript of the multimedia web cam to both the local canvas user and group canvas user. 
         [0066]    The group canvas UI modes (e.g.,  228 ) supersede the local canvas UI modes (e.g.,  226 ) of corresponding local canvases. An administrator and/or collaboration leader may configure how the group canvas UI modes (e.g.,  228 ) supersede the local canvas UI modes (e.g.,  226 ). For example, a group canvas set to the group canvas UI mode of local annotation mode  304  limits the local canvas UI modes to which a local canvas may be set to only include: local annotation mode  304 ; passive mode  308 ; and communication mode  310 . An administrator and/or collaboration leader may set the group canvas UI mode (e.g.,  228 ) to local annotation mode  304  so that a local canvas is only updated in response to user interactions with a corresponding administrator and/or collaboration leader canvas and in response to a user interaction with the respective local canvas. 
         [0067]    A group canvas UI mode (e.g.,  228 ) set to local annotation mode  304  may prevent a local canvas from being updated in response to user interactions with other local canvases corresponding to the group canvas, except in response to user interactions with the administrator and/or collaboration leader canvas. An administrator and/or collaboration leader may set the group canvas UI mode (e.g.,  228 ) to passive mode  308  so that a local canvas is only updated in response to user interactions with a corresponding administrator and/or collaboration leader canvas. A group canvas UI mode (e.g.,  228 ) set to passive mode  308  may prevent a local canvas from being updated, except in response to user interactions with the administrator and/or collaboration leader canvas. The group canvas UI mode (e.g.,  228 ) set to group annotation mode  306  may allow the local canvas UI mode (e.g.,  226 ) to which a local canvas may be set to include: the gadget mode  302 ; the local annotation mode  304 ; the group annotation mode  306 ; the passive mode  308 ; and the communication mode  310 . 
         [0068]      FIG. 4  shows shared surface object metadata  242 . The shared surface object metadata of a shared surface object includes: group canvas shared surface object metadata (e.g.,  402 ,  404 , and  406 ) that corresponds to each group canvas shared surface object representation; local canvas shared surface object metadata (e.g.,  408 ,  410 , and  412 ) that corresponds to each local canvas shared surface object representation; and a shared surface object identifier  414 . The group canvas shared surface object metadata (e.g.,  402 ,  404 , and  406 ) includes: a group canvas identifier  416  that identifies the group canvas to which the shared surface object corresponds; a group canvas shared surface object data type  418 ; and group canvas display properties  420 ; a group canvas shared surface object version  440 . The group canvas identifier  416  identifies a group canvas the boundaries of which at least a portion of a local canvas shared surface object representation is within. The group canvas shared surface object data type  418  may be from a group of data types consisting of: audio  420 ; image  422 ; text  424 ; blob  426 ; and composite  428  that comprises a combination of any two or more of the data types from the group of data types. The group canvas shared surface object data type  418  may include multiple content types, including text snippets, freehand sketches and annotations, images, pointers to shared files, live web pages, and multi-media conferences. 
         [0069]    The local canvas shared surface object metadata (e.g.,  408 ,  410 , and  412 ) includes: a local canvas identifier  430 ; a local canvas shared surface object version  432 ; local canvas shared surface object presentation preferences  434 ; local canvas display properties  436 ; and a local canvas shared surface object data type  438 . The local canvas identifier  430  identifies the local canvas the boundaries of which at least a portion of the local canvas shared surface object representation is within. 
         [0070]    The local canvas shared surface object version  432  specifies the time stamp of a last local manipulation of the local canvas shared surface object representation. The system  102  may use the local canvas shared surface object version  432  to determine how the local canvas shared surface object is presented in the local canvas. The system  102  may also use the local canvas shared surface object version  432  to determine a priority ranking of simultaneous local manipulations of local canvas shared surface object representation. For example, a local manipulation corresponding to a more recent local canvas shared surface object version  432  value may correspond to lower priority ranking. In other words, a simultaneous local manipulation of a local canvas shared surface object representation with the most recent local canvas shared surface object version  432  may be used to generate the corresponding group canvas shared surface object representation. 
         [0071]    In one implementation, an administrator of the system  102  may configure the local canvas shared surface object metadata (e.g.,  408 ,  410 , and  412 ) to correspond to the group canvas shared surface object metadata (e.g.,  402 ,  404 , and  406 ). The group canvas shared surface object metadata (e.g.,  402 ,  404 , and  406 ) may determine the range of values and types of available local canvas shared surface object metadata (e.g.,  408 ,  410 , and  412 ). The service provider logic  212  may analyze the resources available to a local canvas and/or the configuration of the local canvas to determine the availability of particular local shared surface object presentation preferences  434 , the local canvas display properties  436  and the available local canvas shared surface object data types  438 . The service provider logic  212  may analyze the local canvas shared surface object presentation preferences  434 , the local canvas display properties  436  and the available local canvas shared surface object data types  438  to determine whether to update a local canvas shared surface object representation using a translation of a corresponding group canvas shared surface object data type  418 . 
         [0072]    For example, a group canvas shared surface object data type of a group canvas shared surface object representation may correspond to a composite group canvas shared surface object data type  428  that comprises the data types of audio  420  and image  422 , while local canvas shared surface object presentation preferences  434  may indicate a preference for text. The corresponding local display properties  436  may also indicate that audio is unavailable. The service providers  108  responsive to translating audio (e.g., a song arranged with vocals and instruments) to text (e.g., lyrics to a song and/or musical notation of the arrangement of the song) may translate the group canvas share surface object data type  418  so that the local canvas shared surface object representation is presented in the local canvas as text. 
         [0073]      FIG. 5  illustrates shared surface object records  500 , including a group canvas shared surface object record  502  and a local canvas shared surface object record  504 . The system  102  may maintain and store in the shared surface object repository  106 , for each group canvas shared surface object representation  506 , a group canvas shared surface object record  502  comprising the group canvas shared surface object representation  506  based on the shared surface object metadata  242  and the updates of the local canvas shared surface object representation  246  received from the service provides  108 . The group canvas shared surface object record  502  further includes group canvas shared surface object representation metadata  508  (e.g.,  402 ,  404  and  406 ), and a group canvas identifier  510  (e.g.,  416 ) that identifies the group canvas in which a portion of the local canvas shared surface object representation  232  is within the group canvas boundaries of (e.g.,  224 ). 
         [0074]    The group canvas identifier  510  and shared surface object identifier  414  together uniquely identify the group canvas shared surface object representation  506 . In other words, multiple group canvases (e.g.,  116 ,  118  and  120 ) may comprise, within the group canvas boundaries of the respective group canvases, at least a portion of a group canvas shared surface object representation  506 . The system  102  may use the group canvas identifier  510  and shared surface object identifier  414  together to uniquely identify each group canvas shared surface object representation  506 . 
         [0075]    The system  102  may maintain and store in the shared surface object repository  106  a local canvas shared surface object record  504  for each local canvas shared surface object representation  512  (e.g.,  232 ). The local canvas shared surface object record  504  includes the local canvas shared surface object representation  512  based on the local canvas shared surface object metadata  514  (e.g.,  408 ,  410  and  412 ) and the local canvas manipulations (e.g.,  236  and  238 ) corresponding to the respective local canvas (e.g.,  122 ,  124  and  126 ). The local canvas shared surface object record  504  further includes a local canvas identifier  510  (e.g.,  430 ) that identifies the local canvas in which at least a portion of the local canvas shared surface object representation  512  (e.g.,  232 ) is within the local canvas boundaries of (e.g.,  214 ). The local canvas identifier  516  and shared surface object identifier  414  together uniquely identify the local canvas shared surface object representation  232 . 
         [0076]      FIG. 6   a  shows correlations between shared surface objects, group canvases, group canvas shared surface object representations, local canvases and local canvas shared surface object representations  600   a.    FIG. 6   a  illustrates an example correlation of shared surface object identifiers (e.g.,  602 ,  604 , and  606 ) corresponding to shared surface objects, group canvas identifiers (e.g.,  608 ,  610 ,  612 , and  614 ), group canvas shared surface object representations (e.g.,  616 ,  618 ,  620 , and  622 ), local canvas identifiers (e.g.,  624 ,  626 ,  628 ,  630 ,  632 ,  634 , and  636 ) and local canvas shared surface object representations (e.g.,  638 ,  640 ,  642 ,  644 ,  646 ,  648 ,  650 ,  652  and  654 ). 
         [0077]    A shared surface object may correspond to a group canvas comprising a group canvas shared surface object representation, where the group canvas corresponds to multiple local canvases comprising multiple local canvas shared surface object representations. For example, a shared surface object identified by the shared surface object identifier  602  may correspond to a group canvas (e.g., identified by group canvas identifier  608 ) comprising a group canvas shared surface object representation (e.g.,  616 ) and corresponding to local canvases (e.g., identified by local canvas identifiers  624  and  626 ). The local shared surface object representations (e.g.,  638  and  640 ) of the shared surface object identified by the shared surface object identifier  602  correspond to respective local canvases (e.g., identified by local canvas identifiers  624  and  626 ). 
         [0078]      FIG. 6   b  illustrates a first graphical display area  656  that includes a first local canvas  122  (e.g., identified by local canvas identifier  624 ) comprising the local canvas shared surface object representation  638  corresponding to the shared surface object identified by the shared surface object identifier  602 .  FIG. 6   c  illustrates a second graphical display area  658  that includes a fourth local canvas  660  (e.g., identified by local canvas identifier  626 ) comprising the local canvas shared surface object representation  640  corresponding to the shared surface object identified by the shared surface object identifier  602 . The first graphical display area  656  and the second graphical display area  658  may represent multiple respective sources through which a shared user interface surface (e.g., a group canvas identified by group canvas identifier  608 ) is accessible simultaneously by multiple users. In other words, multiple users may use respective graphical display areas (e.g.,  656  and  658 ) to simultaneously manipulate local canvas shared surface object representations (e.g.,  638  and  640 ) of a shared surface object within corresponding local canvases (e.g.,  624  and  626 ). 
         [0079]      FIG. 6   b  further illustrates the first local canvas  122  (e.g., identified by local canvas identifier  624 ), a second local canvas  124  (e.g., identified by local canvas identifier  628 ) and a third local canvas  126  (e.g., identified by local canvas identifier  630 ) comprising respective local canvas shared surface object representations  662  (e.g.,  642 ,  644  and  646 ) corresponding to the shared surface object identified by the shared surface object identifier  604 . Although shown as one local canvas shared surface object representation  662 , each local canvas (e.g.,  122 ,  124  and  126  comprise a respective local canvas shared surface object representation (e.g.,  642 ,  644  and  646 ) corresponding to the shared surface object identified by the shared surface object identifier  604 . 
         [0080]      FIG. 6   b  illustrates that the first local canvas and the second local canvas comprise local canvas boundaries, respectively, where at least a portion of the respective local canvas boundaries common to the first local canvas  122  and the second local canvas  124  may define the third local canvas  126 . The first local canvas  122  and the second local canvas  124  may define the third local canvas  126  may correspond to a group canvas (e.g.,  610 ) comprising group canvas boundaries corresponding to at least a portion of the first local canvas boundaries, the second local canvas boundaries and third local canvas boundaries common to the respective local canvases. 
         [0081]    A shared surface object may correspond to multiple group canvases and local canvases comprising respective group canvas shared surface object representations and local canvas shared surface object representations. For example, a shared surface object identified by the shared surface object identifier  606  may correspond to multiple group canvases (e.g., identified by group canvas identifiers  612  and  614 ) and corresponding local canvases (e.g., identified by local canvas identifiers  632 ,  634 ,  636  and  628 ). The local shared surface object representations (e.g.,  646 ,  648 ,  650  and  652 ) of the shared surface object identified by the shared surface object identifier  606  correspond to respective local canvases (e.g., identified by local canvas identifiers  632 ,  634 ,  636  and  628 ). The group canvases may comprise corresponding group canvas shared surface object representations (e.g.,  620  and  622 ) that correspond to the shared surface object identified by the shared surface object identifier  606 . 
         [0082]    A local canvas may comprise a local canvas shared surface object representation of which at least two different portions correspond to at least two different group canvases. Multiple portions of a local canvas (e.g.,  122 ) may correspond to different group canvases (e.g., group canvases identified by group canvas identifiers  616  and  618 ). A local canvas (e.g.,  122 ) may indicate the group canvas identifiers  232  (e.g.,  616  and  618 ) to which the local canvas corresponds.  FIG. 6   b  illustrates the second local canvas  124  (e.g., identified by local canvas identifier  628 ) comprising local canvas shared surface object representation  654  of the shared surface object identified by the shared surface object identifier  606 .  FIG. 6   d  illustrates a third graphical display area  664  comprising a fifth local canvas  666 , sixth local canvas  668  and seventh local canvas  670  (e.g., identified by local canvas identifiers  632 ,  634  and  636 , respectively). 
         [0083]      FIGS. 6   b  and  6   d  illustrate that the portions of the shared surface object common to the second local canvas  124 , fifth local canvas  666 , sixth local canvas  668  and seventh local canvas  670  may correspond to the third group canvas identified by the group canvas identifier  612 , while the local representations of the entire shared surface object common to the second local canvas  124  and seventh local canvas  670  may correspond to a fourth group canvas identified by the group canvas identifier  614 . The second local canvas  124 , fifth local canvas  666 , sixth local canvas  668  and seventh local canvas  670  comprise respective local canvas shared surface object representations  672  (e.g.,  648 ,  650 ,  652  and  654 ) corresponding to the shared surface object identified by the shared surface object identifier  606 . Although shown in  FIG. 6   d  as one local canvas shared surface object representation  672 , each local canvas (e.g.,  124 ,  666 ,  668  and  670 ) comprises a respective local canvas shared surface object representation (e.g.,  648 ,  650 ,  652  and  654 ) corresponding to the shared surface object identified by the shared surface object identifier  606 .  FIG. 6   d  illustrates that the respective local canvas shared surface object representations  672  (e.g.,  648  and  650 ) represent a portion of the shared surface object, as shown in the fifth local canvas  666  and sixth local canvas  668 , while the respective local canvas shared surface object representations  672  (e.g.,  652  and  654 ) of the second local canvas  124  and seventh local canvas  670  represent the entire shared surface object. 
         [0084]      FIG. 7  illustrates example graphical display area components  700  of a graphical display area  656 . A graphical display area may comprise, in addition to a local canvas (e.g.,  122 ), a graphical display area identifier (e.g.,  702 ) that uniquely identifies the graphical display area (e.g.,  656 ) and inactive local canvases (e.g.,  704  and  706 ). An inactive local canvas (e.g.,  704  and  706 ) represents a local canvas where a local canvas manipulation (e.g.,  236  and  238 ) of the local canvas and/or a local canvas shared surface object representation has not occurred in some specified period of time. The system  102  may use visual queues to indicate that the inactive local canvases (e.g.,  704  and  706 ) are inactive. For example, the local canvas boundaries of the inactive local canvases may each comprise distinct patterns and color. The system  102  may modify the pattern, color and/or size of an inactive canvas, as well as move the local canvas to a particular location within the corresponding graphical display area. 
         [0085]      FIG. 8  illustrates a local canvas shared surface object representation  800  over an elapsed time period during which no local canvas manipulation occurs. A local canvas user may configure the local canvas shared surface object presentation preferences  434  so that a local canvas shared surface object representation  802  is presented in a way that indicates a lack of local canvas manipulation of the local canvas shared surface object representation (e.g.,  804 ,  806 , and  808 ) over an elapsed time period. When no local canvas manipulations occur over an elapsed period of time, the local canvas shared surface object representation (e.g.,  802 ,  804 ,  806 , and  808 ) may change in size, pattern, color (e.g., fade) and reposition in the local canvas so that the local canvas shared surface object representation (e.g.,  808 ) becomes less prominent. Inactive local canvas shared surface object representations and icons and/or avatars of group canvas users may be positioned into the local canvas side-bar  818 . When a local canvas manipulation of a local canvas shared surface object representation (e.g.,  804 ,  806  and  808 ) occurs, the visual appearance and position of the local canvas shared surface object representation  802  may be restored. 
         [0086]    In one implementation, the local canvas tools  1120  include a history and playback feature that may be selected to view a local canvas at a particular point in time and playback the changes that have occurred to the local canvas over an elapsed period of time. The local canvas shared surface object representations of a local canvas may be individually played back and/or synchronized with other local canvas shared surface object representations of the local canvas. For example, the history of viewable changes to a first local canvas shared surface object representation may be played back synchronously with the audio history of a second local canvas shared surface object representation representing an audio record of a discussion that occurred during and about the modifications to the first local canvas. 
         [0087]    The group canvas user identifier  260  and corresponding group canvas status  262  of each group canvas user corresponding to a group canvas to which the local canvas (e.g.,  122 ) corresponds may be represented by an icon and/or avatar (e.g.,  810 ,  812 ,  814  and  816 ) that uniquely identify the group canvas users. The icon and/or avatar (e.g.,  810 ,  812 ,  814  and  816 ) may include colors, patterns and/or text to indicate the group canvas user identifier  260  and corresponding group canvas status  262  of a group canvas user. A local canvas user may select the icon and/or avatar (e.g.,  810 ,  812 ,  814  and  816 ) to initiate communication with the user corresponding to the icon and/or avatar. The group canvas user may receive a request for communication from the local canvas user and optionally accept the request of the local canvas user to communicate. In one implementation, the icon and/or avatar of the group canvas user is brought to the foreground to begin a dialogue in a larger interaction frame (e.g., a group canvas shared surface object representation corresponding to the local canvas user and group canvas user). 
         [0088]      FIG. 9  shows the logic flow  900  that the shared user interface surface system  102  may take to update a local canvas shared surface object representation  232 . The interaction detection logic  210  detects a local canvas user interaction ( 902 ) comprising a local canvas manipulation  236  of a local canvas shared surface object representation  232 . The service provider logic  212  analyzes the shared surface object metadata  242  corresponding to the local canvas shared surface object  232  and communicates the shared surface object metadata  242  and the local canvas manipulations of the local canvas shared surface object representations  244  to service providers  108  responsive to the local canvas shared surface object representation  232  ( 904 ). 
         [0089]    The service providers  108  provide updates of the local canvas shared surface object representation  246  to the respective local canvases canvas manipulations of shared surface object representations  244  ( 906 ). The updates of the local canvas shared surface object representation  246  may be different for each local canvas until the local canvases are synchronized with an updated group canvas shared surface object representation. Where the local canvas user interaction corresponds to a group canvas ( 908 ) and the interaction detection logic  210  detects multiple simultaneous local canvas user interactions ( 910 ) that correspond to the group canvas (e.g.,  118 ), the interaction detection logic  210  may identify a first local canvas user interaction from the simultaneous local canvas user interactions ( 912 ). In other words, the interaction detection logic  210  may consider one of the simultaneous local canvas user interactions to be the first local canvas user interaction. The interaction detection logic  210  updates the group canvas shared surface object representation  506  with the first local canvas shared surface object representation, and the group canvas shared surface object version  440  and the first local canvas shared surface object version  432  to correspond ( 914 ). 
         [0090]    The interaction detection logic  210  may discard a second local canvas user interaction from the simultaneous local canvas user interactions that the interaction detection logic  210  identifies as a second local canvas user interaction. In one implementation, the second local canvas may discover the collision by polling the system for the state of the local canvas shared surface object representation and determine that the local canvas shared surface object representation is stale. The second local canvas may compare the local canvas shared surface object version and group canvas shared surface object version, and determine that the group canvas shared surface object version is more recent. The second local canvas may fetch the group canvas shared surface object representation to update the local canvas shared surface object representation and local canvas shared surface object version. 
         [0091]    The interaction detection logic  210  may generate a group canvas shared surface object record  248 , based on the shared surface object metadata  242  and the updates of the local canvas shared surface object representation  246  received from the service provides  108 . The interaction detection logic may store the group canvas shared surface object record  248  in the shared surface object repository  106 , and update the local canvas shared surface object representation  246  of each of the corresponding local canvases with the group representation ( 916 ). The interaction detection logic  210  may update the group canvases  252  (e.g.,  254 ,  256 ,  258 ) with the group canvas shared surface object record  248  where at least a portion of the local canvas shared surface object representation (e.g.,  232 ) is within the group canvas boundaries of the group canvases. 
         [0092]      FIG. 10  shows the logic flow  1000  that the shared user interface surface system  102  may take to apply local canvas shared surface object presentation preferences. The service provider logic  212  may analyze the group canvas shared surface object metadata  402  of a group canvas shared surface object representation ( 1002 ) and local canvas shared surface object metadata  408  of a corresponding local canvas shared surface object representation ( 1004 ). 
         [0093]    The service provider logic  212  may analyze the group canvas shared surface object data types  418  and/or group canvas shared surface object display properties  420  in relation to the local canvas shared surface presentation preferences  434  and/or local canvas shared surface object display properties  420  to determine whether to use a translation ( 1006 ) of the group canvas shared surface object data types  418  to update the corresponding local canvas shared surface object representation and local canvas shared surface object metadata  408 . For example, the group canvas shared surface object data type of a group canvas shared surface object representation may be audio (e.g., a song arranged with vocals and instruments), while the local canvas shared surface object presentation preferences  434  may indicate a preference for text. The corresponding local display properties  436  may also indicate that audio is unavailable. 
         [0094]    The service providers  108  responsive to particular presentation preferences, data types and display properties may generate updates of the local canvas shared surface object representation  246  based on a translation of the group canvas shared surface object data types  418  ( 1008 ). For example, the service providers  108  responsive to translating audio (e.g., a song arranged with vocals and instruments) to text (e.g., lyrics to a song and/or musical notation of the arrangement of the song) may translate group canvas share surface object data types  418  (e.g., audio  420 ) to text so that a corresponding local canvas shared surface object representation is presented in the corresponding local canvas as text. 
         [0095]    The interaction detection logic  210  may generate a local canvas shared surface object record  504  with the updates of the local canvas shared surface object representation  246  based on the translation of the group canvas shared surface object data types  418  and update the corresponding local canvas shared surface object representation ( 1010 ). 
         [0096]    The system may be implemented in many different ways. For example, although some features are shown stored in computer-readable memories (e.g., as logic implemented as computer-executable instructions or as data structures in memory), all or part of the system, logic, and data structures may be stored on, distributed across, or read from other machine-readable media. The media may include hard disks, floppy disks, CD-ROMs, a signal, such as a signal received from a network or partitioned into sections and received in multiple packets communicated across a network. The system may be implemented in software, hardware, or a combination of software and hardware. The system may also use different message formats, in addition to XML, such as encoded packets with bit fields that are assigned specific meanings. 
         [0097]    Furthermore, the system may be implemented with additional, different, or fewer components. As one example, a processor or any other logic may be implemented with a microprocessor, a microcontroller, a DSP, an application specific integrated circuit (ASIC), program instructions, discrete analog or digital logic, or a combination of other types of circuits or logic. As another example, memories may be DRAM, SRAM, Flash or any other type of memory. The system may be distributed among multiple components, such as among multiple processors and memories, optionally including multiple distributed processing systems. Logic, such as programs or circuitry, may be combined or split among multiple programs, distributed across several memories and processors, and may be implemented in or as a function library, such as a dynamic link library (DLL) or other shared library. 
         [0098]    While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.