[ Thanks to Amy Bennett for this link. ]
The chief improvement in Ruby on Rails 3.2 is in how
the software works in dev, or development, mode. “The new faster
dev mode in particular is a major step up over 3.1,” said Ruby on
Rails creator David Heinemeier Hansson, in a blog post announcing
the release.Most notably, each time a new program is altered and then
tested, dev mode will only reload the classes of that program that
have actually been changed, rather than reload all the classes the
program uses. “The difference is dramatic on a larger application,”
Heinemeier said.