Another incredibly strong release sees the light of day as we move one 
step closer to the mythical 1.0. This release tackles one of the five 
steps on the roadmap in form of caching as well as adding a bunch of 
other cool stuff.

* *Render Caching:* Added an extensive caching module that offers three 
levels of granularity (page, action, fragment) and a variety of stores 
(file, memory, DRb, MemCached).

* *Conditional filters:* It's now possible to limit the actions that a 
given filter will apply to within a controller using either :only or 
:except. Like, <code>before_filter :authorize, :only => [ :edit, 
:delete ]</code>

* *Associating unsaved objects:* Associations between unsaved objects 
makes it much easier to build big graphs that only makes sense to be 
saved together.

* *Database compatibility:* SQLite3 is now supported by the sqlite 
adapter and MySQL 4.1.1+ is also supported by the included Ruby/MySQL 
driver.

* *Numeric bytes and time:* Rails has taken upon itself to extend Ruby 
in a few spots, such as adding the possibility for expressions like 
<code>45.kilobytes + 2.3.megabytes</code> and <code>45.minutes + 
2.hours + 1.fortnight</code>.

Those were the highlights, but Rails 0.9.4 includes no less than 50 
changes, fixes, and features. You can read the full story in the 
changelogs:

* Active Record: http://ar.rubyonrails.com/files/CHANGELOG.html
* Action Pack  : http://ap.rubyonrails.com/files/CHANGELOG.html
* Rails        : http://rails.rubyonrails.com/files/CHANGELOG.html

This release shouldn't require any changes to your application if 
you're coming from Rails 0.9.3.
--
David Heinemeier Hansson,
http://www.basecamphq.com/   -- Web-based Project Management
http://www.rubyonrails.org/  -- Web-application framework for Ruby
http://macromates.com/       -- TextMate: Code and markup editor (OS X)
http://www.loudthinking.com/ -- Broadcasting Brain