lame

Following the great history of GNU naming, LAME originally stood for LAME Ain't an Mp3 Encoder. LAME started life as a GPL'd patch against the dist10 ISO demonstration source, and thus was incapable of producing an mp3 stream or even being compiled by itself. But in May 2000, the last remnants of the ISO source code were replaced, and now LAME is the source code for a fully LGPL'd MP3 encoder, with speed and quality to rival and often surpass all commercial competitors.

LAME is an educational tool to be used for learning about MP3 encoding. The goal of the LAME project is to use the open source model to improve the psycho acoustics, noise shaping and speed of MP3. LAME is not for everyone - it is distributed as source code only and requires the ability to use a C compiler. However, many popular ripping and encoding programs include the LAME encoding engine, see: Software which uses LAME.

Using the LAME encoding engine (or other mp3 encoding technology) in your software may require a patent license in some countries.

LAME features:
•Many improvements in quality in speed over ISO reference software. See history.
•MPEG1,2 and 2.5 layer III encoding.
•CBR (constant bitrate) and two types of variable bitrate, VBR and ABR.
•Encoding engine can be compiled as a shared library (Linux/UNIX), DLL , Directshow filter or ACM codec (Windows).
•Free format encoding and decoding.
•GPSYCHO: a GPL'd psycho acoustic and noise shaping model.
•Powerful and easy to use presets.
•Quality better than all other encoders at most bitrates.
•Fast! Encodes faster than real time on a PII 266 at highest quality mode.
•MP3x: a GTK/X-Window MP3 frame analyzer for both .mp3 and unencoded audio files.