ruby-1.9.3-p327 cumulative performance patch for rbenv without gc patch
This installs a patched ruby 1.9.3-p327 with various performance improvements without a backported COW-friendly GC to make things happy on heroku, all courtesy of funny-falcon.
You will also need a C Compiler. If you're on Linux, you probably already have one or know how to install one. On OS X, you should install XCode, and
brew install autoconf using homebrew.