Lisp

At first I was disappointed there wasn't a Scheme community, but I'm already pleasantly surprised

This is its main web site https://nanopass.org/index.html

Nanopass is a good approach for writing sophisticated compilers, because one can compose many analysis and transformation pass on the AST. For example, Chez Scheme compiler has an extremely good ratio between lines of code and features. It is one of the fastest Scheme compiler, and Scheme is a language difficult to optimize.