Caché is a post-relational database.
It provides several kinds of access to stored data.
Caché has it’s own ORM inside, thus we can communicate with it as with SQL database and use ActiveRecord, but also we can communicate with it as just with part of application with it’s objects.
Also, there is a direct access to Caché internals: callin interface. The most compicated one.
Currently object interface is almost implemented. Source for it is at cache-ruby repository.
Now it is as a gem:
gem install intersys
Project page is intersys at rubyforge
SQL interface works, but Cache really sucks at it. Mysql has a much more complicated set of SQL commands