Charlie is the main force (along with Thomas Enebo) behind JRuby, a JVM-based Ruby implementation that competes extremely well on features and performance with other Ruby implementations. Charlie was instrumental from day one in ensuring that the new invokedynamic functionality worked well for dynamic languages on the JVM. He continues to work on the JVM for other languages today, regularly contributing to the hotspot mailing lists and JVM Language summit etc.
Charlie is a regular conference speaker (Javaone RockStar, OSCON etc) where his deep dive talks on invokedymanic, bytecode and the latest JVM features are always in high demand. He's an OReilly author (Using JRuby), has a well-read blog and Twitter handle (@Headius).
The Java Champions are an exclusive group of passionate Java technology and community leaders who are community-nominated and selected under a project sponsored by Oracle. Java Champions get the opportunity to provide feedback, ideas, and direction that will help Oracle grow the Java Platform.