FreeFeed

Here's their github: https://github.com/FreeFeed/. Everything is MIT licensed as far as I can tell. They did an IndieGogo (https://www.indiegogo.com/projec...) but it's all in Russian so I have no idea what their pitch was. If you didn't use FriendFeed it was a lot like Facebook is now, but with twitter-style follower/following relationships instead of bi-directional friending. FreeFeed also has some nice extra features like being able to moderate comments other people make on your posts. Since you can host your own instance this seems like it would be useful for the sort of thing yammer was meant for; providing a place for people in an organization to write stuff down that isn't ephemeral and isn't tied to a project.