Yesterday the Rails core team announced the official release of Ruby on Rails 3.0.0. Having been in development for over 2 years, Rails 3 is a significant update to the popular web framework and the result of a "project merger" with the Merb framework that happened some time ago.

Along with various members of the Merb team (including Yehuda Katz, whom we recently interviewed), the merger also brought in some newfound modularity and a focus on agnosticism. Although Rails still ships with the strongly opinionated defaults it's famous for, it's now far easier to swap out modular pieces like the ORM persistence layer (via ActiveModel), the testing framework, templating system, and JavaScript libraries.

Many other bits of the framework have been overhauled as well. There's a new vastly improved router syntax to learn, the addition of the ARel query engine, Gemfile dependency management via Bundler, and a better version of ActionMailer that now wraps the newer Mail gem instead of the antiquated TMail.

The official Rails team blog post contains more information or you can dive directly into the release notes for upgrade information. Peter Cooper of RubyInside has also put together a great list of video tutorials that will help familiarize you with the new stack.

Whenever a framework revision involves major internal rewrites like this has, getting a proper stable release out the door can be quite a task and I'd like to personally complement the team on their accomplishment here. My most recent projects have been using the latest Rails 3 release candidates and I must say that this looks like a pretty polished release. At this point, the largest obstacles to upgrade for existing projects are mostly within the Rails Gem plugin ecosystem. Hopefully now that this release is final more plugin authors will find time to incorporate support for the revised plugin API.Yesterday the Rails core team announced the official release of Ruby on Rails 3.0.0. Having been in development for over 2 years, Rails 3 is a significant update to the popular web framework and the result of a "project merger" with the Merb framework that happened some time ago.