There are a few additional ways to extend nginx without writing a module in C.

- JavaScript: https://nginx.org/en/docs/njs/ and https://github.com/nginx/njs-examples

- Lua: https://github.com/openresty/lua-nginx-module

- Rust: https://github.com/nginxinc/ngx-rust

Proxy WASM appears to be supported thanks to a project from Kong: https://github.com/Kong/ngx_wasm_module

I haven't tried it yet, but it looks promising.

I've been interested in learning OpenResty (which is based on the lua-nginx-module). Anybody knows of any interesting codebase using it?

Don't forget Perl.

- Perl: https://nginx.org/en/docs/http/ngx_http_perl_module.html