lwt

Dream doesn't have much of a system call dependency footprint itself. It's basically just a convention for plugging request -> response functions into a web server. Some of its native dependencies will have to be replaced by Node equivalents. Soon after that, it would be portable to Node. There is already work underway to port Dream to Mirage, to run in unikernels: https://github.com/aantron/dream/pull/22 Lwt, Dream's promise library, is itself getting ported to run on top of libuv: https://github.com/ocsigen/lwt/issues/813 libuv is, of course, the I/O library that powers Node, so it might be practical to run Dream as a native node module very soon after doing this. (As an aside, I'm supposed to work on that libuv project, but instead I've been working on Dream :P)

Lwt [1] based web frameworks can be used on MirageOS if they provide an interface that allows someone to swap out the unix dependent pieces. One such framework is Opium [2], that provides most of its features in a unix independent code library `opium_kernel`. Its fairly straightforward to run an opium app on mirage. This example needs to be updated to the newest apis in the released version of Opium but this can provide some hints about how to run an opium app on mirage: https://github.com/anuragsoni/ocaml-opium-unikernel. If a lower level web toolkit is sufficient then ocaml's cohttp [3] library has been available on mirage for quite some time now. [1] https://github.com/ocsigen/lwt/ [2] https://github.com/rgrinberg/opium [3] https://github.com/mirage/ocaml-cohttp/