need open model format suggestions

I am working on a simple game using opengl. I have created a tool to load and render the md2 file format and animations previously. I want to graduate to something a bit heavier duty with skeletal based animations so I can give characters different weapons and armor and have it animate correctly.

What open and well documented model formats are there out there for this. Preferably with easy to use tools to export from open source software like Blender.

I have looked into cal3d but it seems to lack documentation on the file format, expecting you to always interact through it’s library.

While not officially an “open” format, the MD5 format used by Doom3 and the other games based on its engine (Quake 4, Prey, &c) is very well documented. It supports skeletal animation, and there are Blender import and export scripts available for it.

This page <> has all sorts of information about MD5, including links to the documentation for the .MD5MESH and .MD5ANIM files, as well as the Blender exporter/importer.