From the website:

Rails 2.0.2 is a drop-in replacement for Rails 2.0
To upgrade, just do “gem install rails” (if the gems are still not propagated, use—source http://gems.rubyonrails.org) or use the new rel_2-0-2 tag.

The rest of the changes are as follows:

Action Pack

• 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 ml 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]

Active Record

• 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]

Active Resource

• 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]

Active Support

• Ruby 1.9 compatibility. #1689, #10466, #10468 [Cheah Chu Yeow, Pratik Naik, Jeremy Kemper]

• TimeZone#to_s uses UTC rather than GMT. #1689 [Cheah Chu Yeow]

• Refactor of Hash#symbolize_keys! to use Hash#replace. Closes #10420 [ReinH]

• Fix HashWithIndifferentAccess#to_options! so it doesn’t clear the options hash. Closes #10419 [ReinH]

Rails

• 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]

We are proud to announce the BETA release of PRADO 3.1.0. This is the result of nearly one year of hard work from the PRADO Group and represents a major milestone in the PRADO development. We hereby thank all PRADO developers and supporters. Please note, since this is a beta release, part of the code (especially those related with new features) may not be stable and are subject to change. Be very cautious if you intend to use this release in a production environment.

WHAT’S NEW IN THIS RELEASE
- DB access: added three layers of database support, including PDO-based data access, Active Record and SqlMap.
- Active controls: a list of AJAX-enabled Web controls.
- Web services: added SOAP and JSON services.
- TOutputCache: a control that caches selective parts of rendered HTML pages and can improve performance significantly.
- TShellApplication: the base class for PRADO command line application
- TDbCache: a generic cache module using database as persistent storage
- TDbUserManager: a database-driven user manager module
- TClientScriptLoader: a control for loading JavaScript libraries
- Added five new demos, including chat, currency-converter, soap, sqlmap and time-tracker.
- Many minor feature enhancements and bug fixes.

OpenExpedio is our name for open eXtensions to PDO. It’s a light-weight ORB (object-relational bridge) library that works on PHP 4 and 5, and takes advantage of the newly adopted standard for database persistence in PHP 5.1+, PDO. It implements the very simple, but effective Active Record pattern for data access.

jQuery is a new type of Javascript library. It is not a huge, bloated, framework promising the best in AJAX – nor is just a set of needlessly complex enhancements – jQuery is designed to change the way that you write Javascript.

I decided to make a list of the top libraries that I have come across or that I personally use. Libraries can be a web developers best friend. They are great resources to learn from and can save hours and hours of time. These libraries include JavaScript, Ajax, Colors, PHP, and CSS. These should be in any web developers bookmarks, so go ahead and look through these libraries and bookmark your favorite ones. The list is in no particular order.

The Yahoo! User Interface (YUI) Library is a set of utilities and controls, written in JavaScript, for building richly interactive web applications using techniques such as DOM scripting, DHTML and AJAX. The YUI Library also includes several core CSS resources. All components in the YUI Library have been released as open source under a BSD license and are free for all uses. Download the entire library, its documentation and examples from Sourceforge.

The library’s developers blog at the YUI Blog and the YUI Library community exchanges ideas at ydn-javaScript on Yahoo! Groups.

We are pleased to announce that PRADO version 3.0.1 is formally released!

Version 3.0.1 contains about 10 bug fixes and many small enhancements. It also includes a complete weblog demo which should be a good starting point for PRADO users to develop complex Web applications. A few supporting components are also added in this release.

PRADO v3.0.1 may be downloaded at http://www.pradosoft.com/download/.