1. An apparatus, comprising: a processor circuit; and an application program operative on the processor circuit to manage a collaborative document having a presentation surface with multiple constructs, the application program comprising: a document render component operative to render a first document instance of the collaborative document; a document share component operative to receive a document update list comprising a set of change records for a second document instance of the collaborative document, each change record comprising information for a modification made to a construct of the second document instance, determine whether a time stamp of a change record for the first document instance of the collaborative document and a time stamp of a change record for the second document instance of the collaborative document are both within a synchronization interval when the change records have matching constructs, annotate the change records as conflict records, and modify properties of one or more constructs for the first document instance based on the change records to form a merged document instance of the collaborative document; and an undo manager component operative to manage a local undo stack for the first document instance, the local undo stack comprising a set of undo records each storing information to undo a modification made to a construct of the first document instance, compare the set of undo records and the set of change records, and determine whether to preserve one or more of the undo records of the local undo stack after formation of the merged document instance based on one or more of the change records.
1. An apparatus, comprising: a processor circuit; and an application program operative on the processor circuit to manage a collaborative document having a presentation surface with multiple constructs, the application program comprising: a document render component operative to render a first document instance of the collaborative document; a document share component operative to receive a document update list comprising a set of change records for a second document instance of the collaborative document, each change record comprising information for a modification made to a construct of the second document instance, determine whether a time stamp of a change record for the first document instance of the collaborative document and a time stamp of a change record for the second document instance of the collaborative document are both within a synchronization interval when the change records have matching constructs, annotate the change records as conflict records, and modify properties of one or more constructs for the first document instance based on the change records to form a merged document instance of the collaborative document; and an undo manager component operative to manage a local undo stack for the first document instance, the local undo stack comprising a set of undo records each storing information to undo a modification made to a construct of the first document instance, compare the set of undo records and the set of change records, and determine whether to preserve one or more of the undo records of the local undo stack after formation of the merged document instance based on one or more of the change records. 10. The apparatus of claim 1 , the document share component operative to resolve conflict records using a set of construct-based conflict rules without modifying permissions for matching constructs in the conflict records.