What if there was a website that made it dead simple to work publicly on new compilers and learn from others doing the same?

I don't mean like github - I mean you should be able to see and run code in the browser and learn from others by experimenting with others' projects - everything public domain, and only for compilers ..

many languages supported from the start, and chained compilation so one could compile to a different hobby language that further compiles down the chain and in the last step the test program is run - maybe?

HN is a hobbyist community for all kinds of Lisp project. BTW compilers are harder than rocket science, the Dragon book proves it.