SparkleShare is an Open Source collaboration and sharing tool that is designed to keep things simple and to stay out of your way. It's available for Linux distributions, Mac, and Windows.
SparkleShare creates a special folder on your computer. You can add remotely hosted folders (or "projects") to this folder. These projects will be automatically kept in sync with both the host and all of your peers when someone adds, removes or edits a file.
SparkleShare uses the version control system Git under the hood, so setting up a host yourself is relatively easy. Using your own host gives you more privacy and control, as well as lots of cheap storage space and higher transfer speeds. We've made a simple script that does the hard work for you. If you need to manage a lot of projects and/or users it may be worth setting up a GitLab instance.
SparkleShare is Free and Open Source software and licensed under the GNU General Public License version 3 or later. You are welcome to change and redistribute it under certain conditions. Its library SparkleLib is licensed under the GNU Lesser General Public License version 3 or later.
Here are instructions to build SparkleShare on Linux distributions, Mac, and Windows. Make sure to have the git package installed when you're building on Linux.
Website, Twitter, Wiki, and Source Code. Join the chat: #sparkleshare on irc.gnome.org.
Have fun, make awesome. :)