SparkleShare is a file sharing and collaboration app. It works just like Dropbox, and you can run it on your own server. It's available for Linux distributions, macOS, and Windows. Support the project on Patreon.
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.
Under the hood SparkleShare uses the version control system Git and the large files extension Git LFS, 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 we recommend hosting a GitLab Community Edition instance.
SparkleShare is Free and Open Source software and licensed under the GNU GPLv3 or later. You are welcome to change and redistribute it under certain conditions. Its library Sparkles is licensed under the GNU LGPLv3 or later.
Here are instructions to build SparkleShare on Linux distributions, macOS, and Windows.
Official website, Twitter, Wiki, and Source Code.
Have fun, make awesome. :)