I've been talking to James Ladd about this project and it looks really cool. If you don't know, Smalltalk was the language for which the term Object Oriented was coined. It has a rich history and is one of the most powerful languages ever written.
Redline is an implementation of Smalltalk for the JVM. James and his team have some big plans for Redline, but first they want to get to v1.0 with a robust, professional distribution. By running on the JVM, Redline will be able to tap into the amazing ecosystem that is growing around the JVM. That means that interop is incredibly easy between Smalltalk, Java, and Clojure.