I spent a few hours today writing a custom frontend to the Erlang compiler to see what would happen if we built beam files in parallel in a single Erlang VM. I've got it building CouchDB although its not super well tested. Some times for building:
couch_erlc: 0m19.481s master: 1m11.445s master -j4: 0m51.648s Each build was run with: $ git clean -fxd && ./bootstrap && ./configure && time make Except for "master -j4" which just adds -j4 to the make command. It doesn't pass make distcheck yet but I figured I'd throw it out there in case anyone was interested. I'm not entirely convinced its worth the amount of code, but just in case anyone was interested in what about we'd get from using Rebar this should be a pretty close approximation for build times. Code is up here: https://github.com/davisp/couchdb/tree/couch_erlc