[stesch]

There are so many standardized languages out there that have many implementations. Some commercial and some free.

Are there other free Ada compilers out there or is the language too complex for simple enthusiasts to implement a compiler themselves?

Ada isn't owned by one company.

[pjmlp]

Ada has around 6 implementations available, only GNAT is open source.

The language is at the same level as Haskell, OCaml, C++ or similar.