• great runtime performance improvements
• multiple assignments- optional return in if/else and try/catch blocks
• AST transformations and all the provided transformation annotations like @Singleton, @Lazy, @Immutable, @Delegate and friends
• the Grape module and dependency system and its @Grab transformation
• various Swing builder improvements, thanks to the Swing / Griffon (http://griffon.codehaus.org) team
• as well as several Swing console improvements
• the integration of JMX builder
• JSR-223 scripting engine built-in
• various metaprogramming improvements, like the EMC DSL, per-instance metaclasses even for POJOs, and runtime mixins

Via Golem