Rhesus is a script for copying over pre-built templates with optional embedded Erb stuff. It started as a way to make jump-starting Monkeybars apps easier, but the user-defined tempaltes need not have anything to do with Monkeybars.
MonkeyBars provides a structured DSL for safely monkey patching Ruby modules with built-in version checking, method validation, and constant management to prevent silent breakage when dependencies update.