There are libraries that allow C programs and Java programs to interact with Erlang as though they were Erlang processes. From the Erlang Interoperability guide: http://erlang.org/doc/tutorial/overview.html#id61008

The team at Github took another approach, described here: https://github.com/blog/531-introducing-bert-and-bert-rpc It's an old article - so I no idea if it's still in use. The Github sources haven't been updated since 2010.

I don't know how effective it is to chuck around 8MB data structures via message-passing. I have no experience of this myself.