Ruby on Rails 1.2 is finally out, as a release numbered 1.2.1 that updates many key components of the framework. 'Mature' is perhaps the best adjective to describe the latest version. The most important change is arguably "REST, and general HTTP appreciation", to quote the official announcement. In other words, the framework now leverages more advanced features of HTTP. For instance, CRUD operations can now be directly mapped to the native HTTP verbs POST, GET, PUT and DELETE. REST-style mapping simplifies URLs by reducing the need for naming actions in the path, and paves the way to refactoring bloated controllers into simpler, more focused ones. Another major enhancement is better support for UTF-8 encoded strings.
David Heinemeier Hansson appears to have pored over Roy Fielding's PhD dissertation, which defines the acronym REST (Representational State Transfer) as the architectural style of the Web. Fielding is one of the founders of the Apache project, the lead author of the HTTP/1.1 standard, and his work put HTTP and the whole WWW on solid theoretical grounds.
Besides using additional HTTP verbs, Rails controllers can now render multiple formats from the same base URL invoked with different file extensions (i.e. /blog and /blog.rss both invoke the /blog controller, but one renders HTML and the other RSS). David's keynote at the 2006 RailsConf (video, slides) previews these changes, and shows how they support his opinionated (and agile) approach to SOAs without the baggage of SOAP. By digging into HTTP, the Rails team once again shows an easy to follow path towards building web apps the right way.
Ruby is set to finally support Unicode by the end of 2007. Meanwhile, the Rails team has created a Chars class to proxy the native String class and provide encoding-safe operations, such as a slice method that does not mangle multibyte characters. ActiveSupport::Multibyte adds a String::char accessor which returns a Char instance representing the String, so if you do title.chars[0,7] you get a Char instance containing the first seven Unicode characters of the title string (and not the first seven bytes).
It's reassuring the see the Rails team committed not to bells and whistles, but to perfecting the architecture and the infrastructure of the framework. Another sign of maturity: 57 distinct developers sign the changelog for 1.2, more than twice the number in the previous minor releases (27 in 1.1, 18 in 1.0). There are 108 items in the 1.2 changelog, versus 62 in 1.1, which was released in March, 2006. Ruby on Rails definitely seems poised for another year of explosive growth.