The extracted adapter gems are now available for install from the gems.rubyonrails.org server. Say you want the Oracle adapter installed, you just do gem install activerecord-oracle-adapter. All the extracted gems are:

• activerecord-firebird-adapter
• activerecord-frontbase-adapter
• activerecord-openbase-adapter
• activerecord-oracle-adapter
• activerecord-sqlserver-adapter
• activerecord-sybase-adapter

The mysql, postgresql, and sqlite adapters are still included in Rails core.

These will be released to the standard Ruby repository alongside Rails 2.0 when that reaches final.