Nexus PHP is a private PHP bittorrent tracker software similar to the software LegitTorrents is based off of. If you are a content creator or want to start a torrent sharing community this software will be able to get you started with minimal knowledge of programming and servers. As of right now the software is still available off of sourceforge and github but hasn't been developed in a few years.
So this is more of a mirror download just in case. The github page is https://github.com/ZJUT/NexusPHP and the sourceforge page is on the github page. There has been one known bug that has a fix. (https://goo.gl/44Msq3)