The unison port has recently been upgraded from 2.13 to 2.27. The problem is that the protocol has changed between these versions, and unison 2.13 can't talk to unison 2.27: http://trac.macosforge.org/projects/macports/ticket/14172 The only solution that can work in every case (because users may need to do synchronization with machines that only have 2.13 and machines that only have 2.27) is to install the two binaries: unison-2.13 and unison-2.27 (note: when executing the remote unison binary, unison can automatically add its main version number thanks to the addversionno option). So, I think that the best solution is to have a port for the old version unison 2.13 (BTW, this is what Debian does for the 2.9 version and will probably do for the 2.13 version), which installs only the unison-2.13 binary (alternatively, there could be a variant that installs a "unison" binary too for those who don't need unison 2.27). In this case, what should the name of the port be? unison-2.13? unison2.13? -- Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/> Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)