Multiple improvements planned for Web framework upgrade, including Rack integration and more efficient routing A release candidate for version 2.3 of the popular Ruby on Rails Web application development framework is being targeted for release this Sunday, the founder of the project, David Heinemeier Hansson, said on Friday.General release of the platform probably will follow a few weeks later, he said.Rails 2.3 features Rack integration, enabling Rails to work together more easily with other Ruby frameworks; refreshed support for Rails Engines, which are Rails applications that can be embedded within other applications; and nested transactions for Active Record and unified rendering, for easier rendering. More efficient routing also is featured as is Rails Metal, for authoring parts of an application directly in Ruby to boost performance. A release candidate for the ambitious Rails 3 release, which merges Rails with the Merb Web framework, has been expected this May.[ Related: Ruby on Rails on track for major upgrades ] Software DevelopmentDevelopment Tools