Joyent Slingshot 1.0: Make Your Rails App Work Offline
Joyent Slingshot allows developers to deploy Rails applications that work the same online and offline (with synchronization) and with drag into and out of the application just like a standard desktop application. Check its two-minutes tutorial to get a feel of how you can make it work.
We've posted about Slingshot before it was officially released. In addition to stabilizing the overall framework, they also have made several enhancements, including the decision that they will open source the technology (planned for June).
You can find more information on their developer wiki.