This personal Homebrew repository provides Formulas for several software packages I am working on that are too obscure for the official Homebrew taps for now.
For general information on Homebrew, consult the official website
First, add this tap to your Brew. This will to clone Pivotal tap repository and symlink all its formulae.
brew tap tschoonj/tap
Now you will be able to work on those formulae as if there were in canonical Homebrew repository:
brew install gtkmm-plplot
brew install easyrng