Alright, I guess I was mistaken. Thanks for clarifying that.

Well, I think actually Psy-Q has violated copyright law as well. I think ccpsx is based on gnucc. gnucc's license mentions that anyone asking for the source of ccpsx should get it for free, and that they have the right to redistribute it too. I don't know about the other tools included in the SDK.

There's ways to draw primitives without using the TMD format, but AFAIK it's the default format for complex models. I think it's possible to do some optimizations on these files as well, and there's different GsDOBJ handlers for them that affect performance too. As for collision, I'm not sure how to...