I agree. One step towards this is that we would need to track all these points. Perhaps a wiki post on this Discourse or on OCamlverse (cc: @bluddy)?
For instance, I’m currently working on implementing ALPN support which is required for negotiating http2 protocol over TLS on both ocaml-ssl and ocaml-tls. After (and if) this is merged, the next step is changing ocaml-conduit to take advantage of this, which in turn will enable cohttp servers and clients to negotiate “h2” protocol via TLS. I’m not sure about httpaf as it doesn’t seem to use these libraries.
But as has been said, this is unfortunately still a tiny piece of what enables HTTP/2, hopefully other efforts can be done in parallel.
(Btw this thread is getting a bit off-topic from Rust and deeper into missing OCaml libraries, I believe moderators can fork posts to a new topic, e.g. HTTP/2 support–or merge with this one?)