Eric Sessoms announced his Erlang-Scheme interoperability library recently on the PLT discussion list.
What it is: Basically, it’s a port of Distel from emacs lisp over to
scheme. It talks to erlang using its own protocol and impersonates an
erlang node on the network. It aims to provide an abstraction such
that erlang processes look like scheme threads, and vice-versa.
Communication from scheme to erlang is done with (a wrapper around)
thread-send. Messages from erlang to scheme get routed to thread
mailboxes so that they can be picked up with thread-receive.