are there other open source versions of Twitter? I could gladly use this one if ...

mrcactu5 on Dec 31, 2013 | parent | context | favorite | on: Twister: Anonymous, private BtC/DHT/Torrent P2P mi...

are there other open source versions of Twitter? I could gladly use this one if I could embed mathematical equations in it - e.g. with mathJax http://www.mathjax.org/ - and possibly lift the 140 character limit.