I’ve always been confused about Ada the language and its licensing though. I know this project is open source but is the language as well? It’s unclear to me, though I may be missing information
What's mostly not open source (FAFAIK) is SPARK, the formal verification framework for Ada.
It's not a community project, AFAICT. Few people know how to build it from source.
https://github.com/cplusplus/draft
Last time I looked I could not find an equivalent repository for the C standards.
As ISO standards driven language with multiple implementations, commercial and open source ones.
The open source one is part of GCC.
some discussion https://news.ycombinator.com/item?id=27313294