mod_tls is a rustls based replacement for mod_ssl that can be used, more or less, as drop-in replacement. (at least mod_md can configure it) we currently provide no option to build it.
(In reply to Mina Galić from comment #0) This seems to be wrong, no? Docs say: "mod_tls, being written in C, used the Rust implementation of TLS named rustls via its C interface rustls-ffi. This gives memory safe cryptography and protocol handling at comparable performance." So it does not replace mod_ssl with OpenSSL, it is another implementation.
you're, technically, right: it's a replacement in that it can be used instead of mod_ssl, and possibly alongside it, too. not a replacement in: the Apache Httpd project has bet all its horses on this new thing.