Hey guys, Brian Peek from Microsoft just sent me some of the 3DO dev tools. He says the rest of the pack should be released by Redump at some point in the future.
Here is a link:
https://mega.nz/#F!23Y3RQRA!cN7QM6P04jjpPnHQqh5Rjw
For those unaware, the 3DO dev tools were only available for Mac OS. They were notoriously unstable, crashy, and inefficient, to the point where Leo Schwab (a primary 3DO software engineer) called it one of the main reasons the 3DO console failed.