JRuby 0.9.9 Released: Yes, it’s a Big Deal
Hundreds of issues have been resolved including 180 Jira issues and problems with YAML, marshalling and Java integration. Some major performance overhauls of core classes have also occurred. The result is an increase in performance of 40% compared to JRuby 0.9.8. More Ruby (and Rails) software now works on JRuby than ever before, including, finally, the Mephisto blogging system.
JRuby is rapidly becoming a big deal where Ruby is concerned. It could help Ruby succeed in the enterprise where the core implementation has failed. For example, it's already possible to deploy archived Rails applications to the Java-based TomCat application server without too much trouble. Given the locked down nature of many enterprises' hosting environments, JRuby could open up significant new markets for Ruby developers so start playing with it now while it's almost still under the radar.