A method to facilitate sharing information between processing entities that each have a corresponding private data area, comprising: by a control circuit: placing (907, 1003) data corresponding to information from a first one of the private data areas for a first one of the processing entities directly into a second one of the private data areas for a second one of the processing entities without placing the data in an intervening shared data area and without directly invoking a system administrator-like entity configured for accessing private data areas; wherein the data comprises one or more files, wherein the second processing entity declares a globally unique target key, and wherein placing the data comprises employing an invocation framework to transfer the one or more files from the first one of the private data areas to the second one of the private data areas such that the one more files are not exposed to other applications, comprising identifying a target second processing entity using its target key, using the target key to create a private inbox for the target second processing entity, creating a transaction directory in the private inbox, and transferring the one or more file to the transaction directory; in which the invocation framework is arranged to enable a user to send an invoke message to a candidate target; the invocation framework comprising a target for identifying the target for handling invocation, an action for identifying the action to be performed, and data that describes the type and format of the data; and in which, once candidate targets have been identified, the invocation framework performs selection by applying rules in order to identify a single candidate target for the invocation message. by a control circuit: placing (907, 1003) data corresponding to information from a first one of the private data areas for a first one of the processing entities directly into a second one of the private data areas for a second one of the processing entities without placing the data in an intervening shared data area and without directly invoking a system administrator-like entity configured for accessing private data areas; placing (907, 1003) data corresponding to information from a first one of the private data areas for a first one of the processing entities directly into a second one of the private data areas for a second one of the processing entities without placing the data in an intervening shared data area and without directly invoking a system administrator-like entity configured for accessing private data areas; wherein the data comprises one or more files, wherein the second processing entity declares a globally unique target key, and wherein placing the data comprises employing an invocation framework to transfer the one or more files from the first one of the private data areas to the second one of the private data areas such that the one more files are not exposed to other applications, comprising identifying a target second processing entity using its target key, using the target key to create a private inbox for the target second processing entity, creating a transaction directory in the private inbox, and transferring the one or more file to the transaction directory; in which the invocation framework is arranged to enable a user to send an invoke message to a candidate target; the invocation framework comprising a target for identifying the target for handling invocation, an action for identifying the action to be performed, and data that describes the type and format of the data; and in which, once candidate targets have been identified, the invocation framework performs selection by applying rules in order to identify a single candidate target for the invocation message. placing the data comprises employing an invocation framework to transfer the one or more files from the first one of the private data areas to the second one of the private data areas such that the one more files are not exposed to other applications, comprising identifying a target second processing entity using its target key, using the target key to create a private inbox for the target second processing entity, creating a transaction directory in the private inbox, and transferring the one or more file to the transaction directory; in which the invocation framework is arranged to enable a user to send an invoke message to a candidate target; the invocation framework comprising a target for identifying the target for handling invocation, an action for identifying the action to be performed, and data that describes the type and format of the data; and in which, once candidate targets have been identified, the invocation framework performs selection by applying rules in order to identify a single candidate target for the invocation message.