The paper on Awareness and Coordination in Shared Workspaces [2] distinguishes between synchronous , and asynchronous awareness information. Synchronous awareness information is presented as it happens. A good example for synchronous activity is the shared cursor location marker that is often implemented in collaborative software. Asynchronous awareness information provides an overview of what happened in the past. The user may use this information to get a short update what happened in the past. The most common implementation of asynchronous activity visualization are change bars - margin marks indicating text areas which have been changed. change bars are very helpful when combined with an edit history to provide context for the user.