Just like Unitystation, Space Station 14 is another game attempting to revive the classic RPG Space Station 13 with cross-platform support on a more modern platform. Not just a remake though as SS14 will be including more advanced graphical features too.
Space Station 14 is a free and open source remake and a continuation of an earlier attempt. Unlike Unitystation though, Space Station 14 doesn't require contributors to use a proprietary game engine (Unity) making it much more open.
It was designed to be extensible too, so you will be able to run your own servers that can change whatever rules you want to provide different experiences and settings. It seems people who ran game servers for SS13 will be porting over to SS14 too, including a popular Colonial Marines mode as they announced in a blog post earlier this year.