JRuby 1.4.0 is now available (JRuby 1.4 download links).
InfoQ covered the changes and new features in JRuby 1.4 release candidates which were already nearly feature complete.
One addition late in the release cycle was a native launcher for JRuby on Windows. Vladimir Sizikov explains the native launchers advantages over the old .bat file based launcher:
I’ve been fixing some JRuby BAT launcher script errors recently, and it was tricky, as always: as soon as you fix one issue with the way the BAT file parses parameters, a new one pops up (and a couple of regressions on top of that). Spaces, brackets, quotes, & and ^ signs, you name it. We’ve been playing this game for years now, and every time it just gets uglier and uglier. [..]
[T]he JRuby native launcher for Windows [..] has nice Java detection, an ability to launch Java in-process (so in the Task Manager one can see jruby.exe process, not just java.exe), it handles most of JRuby command line arguments already, it allows to pass parameters to the JVM when needed (via –J switch, like we always did), and it can handle spaces and brackets in the path, etc.
Vladimir also mentions the proper way to check for the OS version Ruby runs on:
require ‘rbconfig’
WINDOZE = Config::CONFIG[‘host_os’] =~ /mswin|mingw/
Vladimir's blog post contains more details and the reasons why this is preferable.
Finally, Nick Sieger announces a new version of _why's Hpricot, a popular library for accessing HTML/XML. Hpricot 0.8.2 is available from Rubyforge. The new version addresses long standing issues (JRUBY-3732 explains the history) and makes Hpricot work on JRuby again.