CoHTTP is an OCaml library for creating HTTP daemons. It has a portable HTTP parser, and implementations using various asynchronous programming libraries:

• Cohttp_lwt_unix uses the Lwt library, and specifically the UNIX bindings.
• Cohttp_async uses the Async library.
• Cohttp_lwt exposes an OS-independent Lwt interface, which is used by the the Mirage interface to generate standalone microkernels (see the mirage-http repository).

You can implement other targets using the parser very easily. Look at the lib/IO.mli signature and implement that in the desired backend.

You can activate some runtime debugging by setting COHTTP_DEBUG to any value, and all requests and responses will be written to stderr.

For build requirements, please see the _oasis file, or use OPAM to install it from http://github.com/ocaml/opam.

Simple HTTP server

If you install the Async dependency, then a cohttp-server-async binary will also be built and installed that acts in a similar fashion to the Python SimpleHTTPServer. Just run cohttp-server-async in a directory and it will open up a local port and serve the files over HTTP.

There is also an Lwt version of the SimpleHTTPServer installed as the cohttp-server-lwt binary. The source code for both is in the bin/ subdirectory and is a good starting point for how to write servers using the library.