Patent ID: 8024661

Claim:
A method for one or more users to collaborate on an actual stored drawing document across a network, comprising: (a) maintaining a single actual stored drawing document on a server; (b) the server establishing a collaboration session wherein multiple users on multiple client computers collaborate in real time and dynamically view modifications, executed by any one of the multiple client computers to a local copy of the single actual stored drawing document, performed in real time by any one of the multiple users on the client computers in the collaboration session, wherein during the collaboration session: (i) the multiple client computers maintain simultaneous write access to the single actual stored drawing document; (ii) asynchronous commands are received by the server that are generated and transmitted from one or more of the multiple client computers, wherein the asynchronous commands: (1) have a delay between each asynchronous command of a fixed time period, wherein the fixed time period depends on whether the one or more client computers comprise a single client computer or multiple collaborating client computers having one specific value for a single client computer and a different specific value for multiple collaborating client computers; (2) include any modifications made in real time by the user on the client computer that is transmitting the asynchronous command; (3) cause the server to transmit any modifications to all of the multiple client computers in the collaboration session; (4) the asynchronous commands comprise a strong heartbeat received from a transmitting client computer; (5) the strong heartbeat command does not comprise a data modification command; (6) in response to receipt of the strong heartbeat, the server will not timeout a workspace session of the transmitting client computer and will not mark the workspace session as inactive; and (iii) the server maintains a history of all modifications to the actual stored drawing document, wherein any of the one or more multiple client computers in the collaboration session can undo any user's modifications using the history.