JRuby 1.1.5 is now available (JRuby download page).
The main changes, from the release notes:
- Per-class method caching (improves __send__, respond_to?, and defined?)
- Constant cache dramatically improves constant lookup
- Reduced memory usage for compiled execution
- Several Java Integration regressions fixed
The Constant cache was described in bug "JRUBY-3052 Cache Constants at their call site (const_node)", the Github commit of Constant caching shows what was involved in the change.
Ruby-ffi, which is now available for Ruby MRI as well as Rubinius, has been shipped with JRuby since 1.1.4. In 1.1.5 to include ruby-ffi includes callback support, which allows to pass Ruby blocks to functions that expect a callback function.
JRuby 1.1.5 also fixes the DOS vulnerability in REXML (InfoQ's coverage of the vulnerability).
Finally, JRuby 1.1.5 ships with RubyGems 1.3.1.