Data Jockey is a FLOSS software project, in essence a digital disc jockey tool which leverages audio meta-data (both computed and manually added by the user) in order to allow for new approaches in content selection and juxtaposition. While there are other software tools that allow users to DJ digitally, none focus as heavily on search and comparison between audio works using audio meta-data.
These are 2 simple c++ classes that wrap the jack audio io and lock-free ringbuffer.
Originally called avr-midi this library has evolved much over time. It is now a relatively device independent library for sending a receiving midi. The target platform is still a microcontroller, but there is no reason it couldn't be useful elsewhere.
A FLOSS *nix editor for the Dave Smith Instruments Evolver synthesizer.