From Testbit Wiki
What are BEAST and BSE?
Beast is a music composition and modular synthesis application released as free software under the GNU LGPL, that runs under Unix. It supports a wide range of standards in the field, such as MIDI, WAV/AIFF/MP3/OggVorbis/etc audio files and LADSPA modules. It allows for multitrack editing, unlimited undo/redo support, real-time synthesis support, 32bit audio rendering, full duplex support, multiprocessor support, conditional MMX/SSE utilisation for plugins, precise timing down to sample granularity, on demand and partial loading of wave files, on the fly decoding, stereo mixing, FFT scopes, MIDI automation and full scriptability in scheme. The plugins, synthesis core and the user interface are actively being developed and translated into a variety of languages, regularly assimilating user feedback.
Here is an extensive screenshots page, showing beast in action.
BEAST is an abbreviation for Better Audio System. BSE an abbreviation for Better Sound Engine, it implements all the neccessary music processing logic required by BEAST in a separate reusable library. The "Better" portion of the names refer to the complexity and many iterations involved in implementing such a "BEAST". :-)
For discussions/feedback relating to BEAST or this page, refer to the Beast Mailing List.
For a collection of articles relating to BEAST and past news about the project, refer to our historic section.