Beryl forked from Compiz last year, from the community branch of Compiz maintained by Quinn Storm. At the time, Storm said that the split was amicable but necessary because the two projects had different goals. Now, it seems, the projects have found common ground. According to a post on the Compiz forum:
As many of you already know, there have been sporadic discussions with members of the Beryl community over the last few weeks regarding the possibility of reuniting. While these discussions have been informal, they have led to greater cooperation between the communities.
Shortly after I published the description of the proposed restructuring of compiz, Quinn Storm of Beryl published a proposed redefinition of Beryl that was very similar. After some discussions with the Beryl community we came to the conclusion that that Compiz-Extra and Beryl would be nearly identical projects competing against each other using the same (or very similar) core, the same plugins, and having goals that were very similar. The obvious question then became: "Why are we competing?"
At this point we are actively discussing the possibility of reuniting. Many of the issues that caused the fork and have kept us apart are now resolved or irrelevant. The idea we have discussed is combining the Compiz-Extra and Beryl communities under a new name.
The name "Coral" is being discussed as an alternative. Compiz would continue to exist as a core package and the remainder of the project would focus on "plugins and other programs that provide functionality which is not essential to the operation of the core."
Storm says that the Beryl project reserves "the right to re-fork" if there's any "loss of freedom" resulting from the merger.
However, Storm says that is not much of a concern and that the resulting change in opinion is due to paying attention to comments from users and developers. "I hope for good things in the future for all of us."