GL Viewport
This is the test program I wrote when I was learning OpenGL. At first it was part of the MAX exporter, and the GL viewport was overriding the active viewport in MAX to replay a scene. This is a replayer for all the exported things. The usual version supports standard techniques (skinning, motion blending…) as well as really experimental ones (speech recognition using Microsoft's Speech API !).
You can download a limited version here.
NB: Don't try to read ZCB files from Flexporter with it, the expected format is an old one....