ID3 mass tagger is a portable command-line mass tagger for audio files. It is designed for non-interactively adding, removing, or updating meta-information in a number of files with a single command. It can generate tag fields from the filename and rename files using an intuitive syntax. It currently supports ID3 (1.1), Lyrics3 (2.0), and ID3v2 (2.0 and 3.0) tags.
Mup produces very high quality PostScript printed music or a MIDI file from a text input file. It can handle almost any kind of music, instrumental or vocal, including tablature, shaped notes, guitar grids, alternate tunings, user-defined symbols, and much more. Mup has been under active development since 1992.
Sfront compiles MPEG 4 Structured Audio (MP4-SA) programs into efficient C programs that generate audio when executed. MP4-SA is a standard for normative algorithmic sound, which combines an audio signal processing language (SAOL) with score languages (MIDI and SASL). Under Mac OS X and Linux, sfront supports real-time, low-latency audio input/output and MIDI input. Under Mac OS X, sfront supports the creation of AudioUnit plug-ins. The documentation includes a book about SAOL programming.