Facebook Read Eval Log Loop is an interactive environment for exploring the Facebook Connect JavaScript SDK. The SDK is available here.
You'll need these to make modifications to rell:
Install the main command which will automatically pull Go dependencies, then use npm to fetch JavaScript dependencies.
go get -u github.com/daaku/rell
cd $(go list -f '{{.Dir}}' github.com/daaku/rell)/js
npm install
rell -h