This is wonderful news! Inform has been one of the most interesting programming languages for a long time, but it was always a fatal flaw that it was unfree. I'm so happy to hear that problem has finally been solved!
Inform 6 and the Inform6 English library were free but not if7.
You could code Z-Machine games freely (as in freedom) with an OOP language 1000 times simpler than Python and the English library handling everything for you.
Sure but Inform 6 and Inform 7 are essentially entirely unrelated thought processes; like, I definitely consider Inform 7 to be one of the most fascinating--if, though, at least to my sensibilities: "ridiculous"--programming languages ever designed (and actually used), while Inform 6... is a programming language, sure ;P.
It's under the Artistic License 2.0: https://github.com/ganelson/inform