A stable release of the Ruby 1.9 series has now been around for a few months, but most developers are still using Ruby 1.8. Why is this? Ruby 1.9 is faster and uses less memory than 1.8; it also has Continuations that don't leak memory, just to name a few of the numerous advantages.
Antonio Cangiano, known for his Great Ruby Shootouts, has an explanation why so few have switched:
Some developers wrongly believe that Ruby 1.9 is just one intermediary step to Ruby 2.0, and as such it’s not meant to be used in production. Better communication could have avoided this common misconception. More importantly though, developers are not using Ruby 1.9 because there are very few libraries that work with it.
InfoQ recently reported on Ruby 1.9.1 library compatibility. Cangiano even sees a positive aspect in the 1.9 upgrading activity:
This switch to Ruby 1.9.1 can also act as a reset button when it comes to getting rid of many of the old, unmaintained, half-assed attempts from N years ago. Porting to Ruby 1.9.1 could act as a rough, implicit line of distinction between active and inactive projects.
While Cangiano tries to motivate projects and the community to put more effort into the 1.9 upgrade, Rob Kaufman has an interesting idea:
What if instead of trying to make every project maintainer learn all the tricks and skills needed to convert a piece of code to 1.9, we put up a little money to get one expert to work on converting gems over. Someone to work with maintainers to get their gems up to date. Someone who would gain practice as he converts gem after gem and who would dedicate real hours to making this conversion done.
Kaufman offers himself for that position and tries to raise money to finance the project, something Gregory Brown did for his work on the PDF library Prawn. Several approaches are possible, one could start with the most downloaded Gems from Ruby Forge, starting with a framework like Rails or Merb and its plug-ins or based on the reports on Is it Ruby 1.9. People can vote on the Ruby 1.9 Or Bust blog.
If you are interested in a faster Ruby 1.9 adoption, the Ruby 1.9 Or Bust project can be supported via Pledgie.