Note:
Unison is no longer under active development as a research project. (Our
research efforts in this area are now focused on a follow-on project called
Harmony. At this point, there is no one whose job it is to maintain Unison, fix
bugs, or answer questions.
However, the original developers are all still using Unison daily. It will
continue to be maintained and supported for the foreseeable future, and we will
occasionally release new versions with bug fixes, improvements (sometimes large
ones), and contributed patches.
more infos: http://www.cis.upenn.edu/~bcpierce/unison/status.html