Graveyard is a collaborative editing systems based on the Operational Transformation approach. It allow users to edit the same document from multiple sites across Internet. Each user hosts a replica of this text document and can modify it at anytime. Modifications performed by a user are sent to all other users. The integration of remote modifications is totally automatic. After integrating all modifications, all sites host the same content.
Graveyard supports real-time editing: modifications made by a user are integrated as soon as possible to all replicas Unlike existing real-time editors such as Gobby, Graveyard works over Wide Area Networks. Graveyard allows also asynchronous collaborative editing. In this case, the user decides when remote modifications are integrated.Any user can switch from one mode to the other one at anytime.
Graveyard does not require a central server. All sites have the same role. This architecture improves reliability (since a central server is a single point of failure) and distributes network traffic.
Graveyard can be used with the MOT2 algorithm which provides a P2P reconcilliation. Therefore, we obtain a P2P collaborative text editor.
In single user editor, the undo feature is mandatory. A user must be able to recover from
erroneous modifications. In a collaborative editor, this feature is called group undo. Group undo
is even more important due to parallel editing. Graveyard allows any user to undo any modifications
at anytime. For example, a user can undo all modifications made by a malicious user.