There are lots of tools which can export to md2. I've never actually animated in this tool but one free tool which is practically a necessity when working with md2 files is Q2 Modeller, a piece of freeware that can be downloaded from the Eldermage site (I think; it keeps moving around.) Just search on Google. While I've never actually modeled or animated in Q2 Modeller I have used it for other editing tasks like naming the frames in the md2 file.
For just a tiny bit of money however you can pick up tools like Milkshape, CharacterFX, and Ultimate Unwrap which have very robust export to md2 file format. Those tools are useful for so many other things too that it is worth not going to see a movie or ordering pizza one weekend (that's literally how inexpensive they are.)
For just a tiny bit of money however you can pick up tools like Milkshape, CharacterFX, and Ultimate Unwrap which have very robust export to md2 file format. Those tools are useful for so many other things too that it is worth not going to see a movie or ordering pizza one weekend (that's literally how inexpensive they are.)