I know I'm dreaming, Stephen is rather on the opposite side, but if he would open source it all/most of it, he'd be one of the most famous people around. I wonder how he'd move financially wise with that kind of bold move?
Seems like he's far from open sourcing it. His team just published a long blog post ( https://blog.wolfram.com/2019/04/02/why-wolfram-tech-isnt-op... ) explaining why they're closed source.
As a matter of fact a large part of the Mathematica codebase is inspectable (the part that is written in Mathematica itself) [1].
Disclaimer: I'm a Wolfram employee, but these are my opinions and any decision on open sourcing the language would be way above my pay grade.
[1] https://mathematica.stackexchange.com/questions/1742/what-is...