LAME

LAME is a high quality MPEG Audio Layer III (MP3) encoder licensed under the LGPL. It is considered the best MP3 encoder at mid-high bitrates and at VBR.

Free Open Source Mac OS X Windows Linux BSD

Vorbis

Ogg Vorbis is a fully open, general-purpose compressed audio format for mid to high quality (8kHz-48.0kHz, 16+ bit, polyphonic) audio and music at fixed and variable bitrates from 16 to 128 kbps/channel.

Free Open Source Mac OS X Windows Linux

Opus Interactive Audio Codec

Opus is a totally open, royalty-free, highly versatile audio codec. Opus is unmatched for interactive speech and music transmission over the Internet, but also intended for storage and streaming applications.

Free Open Source Mac OS X Windows Linux

Matroska

The Matroska Multimedia Container is an open standard free container format, a file format that can hold an unlimited number of video, audio, picture, or subtitle tracks in one file.

Free Open Source Mac OS X Windows Linux Android

Apple Lossless

Apple Lossless (also known as ALAC) is an audio codec developed by Apple Inc. for lossless data compression of digital music. Apple Lossless data is stored within an MP4 container with the filename extension .

Free Open Source Mac OS X Windows

WavPack

WavPack is a completely open audio compression format providing lossless, high-quality lossy, and a unique hybrid compression mode.

Free Open Source Mac OS X Windows Linux

Nero AAC Codec

Nero AAC reference quality MPEG-4 and 3GPP audio codec - Compression ratios ranging from Ultra High (58 CDs fit on one!) to High-End Audio (2.

Free Personal Windows Linux

TAK

»TAK – [T]om’s lossless [a]udio [k]ompressor / [T]oms verlustfreier [A]udio[k]ompressor – is, as the name already suggests, a lossless audio compressor, similar to...

Free Windows Winamp foobar2000