It's been almost a year since the release of Ruby 1.9.0, the first release of the Ruby 1.9.x branch. However, at the time that it was released the core team indicated that this was strictly a development release and not intended for production. Yesterday, Yuki Sonoda officially announced the availability of Ruby (MRI) 1.9.x, which is the first production-ready release of the 1.9.x branch -- exciting news!

At this point, new language features for the 1.9.x line are effectively frozen, and this is a great time for developers to dive in and learn about the changes from 1.8.x and the new idioms in place. It's also a good time to start porting any of your Ruby libraries and projects over to 1.9, and fixing any problems caused by incompatibilities between 1.8 and 1.9.

I won't waste precious breath here to run through every change to Ruby itself or to its standard libraries; instead I'll be happy to refer you to the changelist above and the excellent coverage at the following sites:

• What's Changed in Ruby 1.9
• Installing Ruby 1.9.1 Screencast
• Excellent RubyInside Coverage and Resources

Of course this isn't quite the end of the line for 1.8.x either (1.8.8 will be released "this year"). And it will no doubt be some time before all of the familiar libraries, gems, and frameworks in the Ruby community are quite up to speed and 1.9 compatible. This is why it's especially important for OSS developers to start updating their projects as soon as possible.

I had no trouble at all installing 1.9.1 from source and running a few simple command line scripts that I'd written, but immediately had issues trying to run one of my more complex Rails projects which relies on a number of third party RubyGems. I also had issues installing Passenger, which relies on Fast Thread -- which is apparently not yet working under 1.9. Ryan Bigg has recently written about his struggles getting an edge Rails application running on the latest release in more depth.

All in all, 1.9.1 is a solid step forward for MRI, and greatly improved benchmark results and a handful of new language features make this an exciting time for the Ruby community. Visit http://www.ruby-lang.org for more information, discussion, and (of course!) downloads.