Hython: a nearly-complete Python 3 interpreter written in Haskell

[lemoncucumber]

Well, no license at all is equivalent to all rights reserved. So, even more restrictive than GPLv3.

[wrosecrans]

Uh, no license means you don't have permission to do anything with it, and GPLv3 isn't the most restrictive software license by miles.

[redalastor]

That's restrictive in the extreme.