JRuby 1.1.3 is the third point release of JRuby 1.1.  The fixes in the release are primarily performance enhancements and compatibility resolutions. 

In an email interview Thomas Enebo states, "Our goal is to put out point releases more frequently for the next several months (about 3-4 weeks a release). We want a more rapid release cycle to better address issues brought up by users of JRuby."

Highlights include:
- RubyGems 1.2
- Greatly improved interpreter performance
- jrubyc compiler usability improvements and bug fixes
- Reduced memory usage and object churn
- Dozens of IO-related and core class RubySpec fixes + reduced memory for IO
- ThreadGroup fixes to resolve Mongrel "dead thread" issues
- New options/properties for tweaking JIT, thread pooling, and more
- Block invocation performance improvements
- Much faster Time performance
- Much better support for --debug
- 82 issues resolved since JRuby 1.1.2

Check out the site and download the code.