MO3 module format
Platform: Win32, OSX, LinuxCurrent version: 2.4
   download - Win32 download - MacOSX download - Linux
MO3 is a file format, encapsulating the features of several "MOD" formats (IT, XM, S3M, MTM, MOD), but with one big difference: MP3 and OGG compressed samples. A lossless codec is also incorporated for any samples that don't like lossy encoding, and the whole file structure is compressed too.

All of this makes it possible to have great reductions in file sizes with practically identical sound quality. In fact, MO3 allows greater quality compositions because MP3/OGG encoding works better with 16-bit samples, so there's no reason to use low quality 8-bit samples anymore.
Main features
Other stuff
downloadUNMO3 library
A library that allows other software to decompress MO3 files. The following platforms are supported: Windows, OSX, Linux, iOS, Android.
download - Win32
download - MacOSX
OGGENC 1.4.0 (libvorbis 1.3.2)
OGG encoder for creating MO3 files. It will generally come preinstalled with Linux distributions.
The recommended MP3 encoder for creating MO3 files.
downloadUNMO3 + BASSMOD example
A simple example of using UNMO3 with BASSMOD, demonstrating how UNMO3 can be used to add MO3 support to other software. Also see the BASSMOD XMMS plugin for another example.