Or use Tra, by Russ Cox (Plan 9 and Go guru). It can handle more than two machines.

Unison is unfortunately no longer under development.

http://www.cis.upenn.edu/~bcpierce/unison/status.html

true, though the devs still use it and release bug fixes.

Theres nothing to rule out folks taking active ownership of dev work on the project, eg take the time to go to their svn repo http://www.seas.upenn.edu/~bcpierce/unison//svn-instructions... and eg run hg/git/darts import on the repo...

Also, if you look at the svn repo, its been touched with as recently as the past 8 weeks. thats pretty good for a project thats not active

unison is quite nice, but it does require being both sides, which can be problematic sometimes.

Another annoyance with unison is that you must have the same version of unison on both hosts. It's a pain if you have (say) 2 different releases of ubuntu.