RAILTIES

* Changed the default database from mysql to sqlite3, so now running “rails myapp” will have a config/database.yml that’s setup for SQLite3 (which in OS X Leopard is installed by default, so is the gem, so everything Just Works with no database configuration at all). To get a Rails application preconfigured for MySQL, just run “rails -d mysql myapp” [DHH]
* Turned on ActionView::Base.cache_template_loading by default in config/environments/production.rb to prevent file system stat calls for every template loading to see if it changed (this means that you have to restart the application to see template changes in production mode) [DHH]
* Introduce `rake secret` to output a crytographically secure secret key for use with cookie sessions #10363 [revans]
* Fixed that local database creation should consider 127.0.0.1 local #9026 [parcelbrat]
* Fixed that functional tests generated for scaffolds should use fixture calls instead of hard-coded IDs #10435 [boone]
* Added db:migrate:redo and db:migrate:reset for rerunning existing migrations #10431, #10432  [matt]
* RAILS_GEM_VERSION may be double-quoted also.  #10443 [James Cox]
* Update rails:freeze:gems to work with RubyGems 0.9.5.  [Jeremy Kemper]

ACTIVERESOURCE

* Added more specific exceptions for 400, 401, and 403 (all descending from ClientError so existing rescues will work) #10326 [trek]
* Correct empty response handling.  #10445 [seangeo]

ACTIONPACK

* Added delete_via_redirect and put_via_redirect to integration testing #10497 [philodespotos]
* Allow headers[‘Accept’] to be set by hand when calling xml_http_request #10461 [BMorearty]
* Added OPTIONS to list of default accepted HTTP methods #10449 [holoway]
* Added option to pass proc to ActionController::Base.asset_host for maximum configurability #10521 [chuyeow]. Example:

   ActionController::Base.asset_host = Proc.new { |source|
     if source.starts_with?(‘/images’)
       “http://images.example.com”
     else
       “http://assets.example.com”
     end
   }

* Fixed that ActionView#file_exists? would be incorrect if @first_render is set #10569 [dbussink]
* Added that Array#to_param calls to_param on all it’s elements #10473 [brandon]
* Ensure asset cache directories are automatically created.  #10337 [Josh Peek, Cheah Chu Yeow]
* render :xml and :json preserve custom content types.  #10388 [jmettraux, Cheah Chu Yeow]
* Refactor Action View template handlers.  #10437, #10455 [Josh Peek]
* Fix DoubleRenderError message and leave out mention of returning false from filters.  Closes #10380 [Frederick Cheung]
* Clean up some cruft around ActionController::Base#head.  Closes #10417 [ssoroka]

ACTIVERECORD

* Ensure optimistic locking handles nil #lock_version values properly.  Closes #10510 [rick]
* Make the Fixtures Test::Unit enhancements more supporting for double-loaded test cases.  Closes #10379 [brynary]
* Fix that validates_acceptance_of still works for non-existent tables (useful for bootstrapping new databases).  Closes #10474 [hasmanyjosh]
* Ensure that the :uniq option for has_many :through associations retains the order.  #10463 [remvee]
* Base.exists? doesn’t rescue exceptions to avoid hiding SQL errors.  #10458 [Michael Klishin]
* Documentation: Active Record exceptions, destroy_all and delete_all.  #10444, #10447 [Michael Klishin]

ACTIONMAILER

* Included in Rails 2.0.2