With Starcraft II, Blizzard have introduced MDX3 (.m3). It's the latest version of the MDX format, which has been used since Warcraft III.

The goal of this project is to document the format, along with developing code to read/write/edit these files.

Blizzard is using 3ds Max with an importer/exporter plugin, so making an importer/exporter for the format should be fairly possible as soon it's documented.

Credits

I (nneonneo) am just mirroring this repository from Google Code (https://code.google.com/p/libm3). All credit for this work goes to the original authors, Richard Geslot and madyavic.