Comment on Unison File Synchronizer

janglinus: you are definitely right, we should document this. In the meantime, clicking on any entry will give you some information in the bottom that detail the states of both files, which could help you figure out what the changes are. Here is a quick description of the icons:
circle filled with blue: changed file
circle filled with gray: unchanged file
gray circle filled with white: absent file (it is not there and was not there before)
green circle with plus: new file (it is there and was not there before)
red circle with x: deleted file (it is not there but was there before)
~: permission change (they are orthogonal to contents change)

Hope this helps,