Rhythmbox Microblogger can send notices about your current music to a microblogging service from Rhythmbox (it currently supports Twitter and Identi.ca). You can edit text before sending a post, and use your own template.
Dianara is a client for the pump.io social network. It allows users to manage their pump.io social network accounts without using a Web browser.
A mod player library.
Software to help transcribe recorded music.