CollaborationFramework: a toolkit for sharing existing single-user applications without modification

There are two conventional approaches to building synchronous collaborative applications: collaboration unaware and collaboration-aware. Though the unaware approach, realized by graphic level synchronization, has an advantage in that it does not require any modification of the original single user applications, it makes it difficult to support groupware specific operations. On the other hand, the aware approach makes it possible to include such features, but only at the cost of rewriting the original application. Our CollaborationFramework provides a platform that is unique in combining the two approaches. It supports construction of an aware external program for controlling the original software application. The scheme is useful for the type of applications in which interfaces for querying and setting the internal status are well defined. We demonstrated the effectiveness of our approach by making off-the-shelf WWW browsers into a shared version with groupware specific synchronization capability.