Is it possible to use Non-relatiional Datbase with Ruby on Rails for Web app ?
Well ActiveRecord won't support it but that doesn't stop you from
using the rest of rails with it (eg I'm working on an app that uses
couchdb for storage).
Of course you can use them. If you are using CouchDB, then there
(http://github.com/arunthampi/activecouch/tree/master) which will give
you ActiveRecord like interface. If you are planning to use some other
DB, you can help community like ActiveCouch guys by extracting your
code and releasing it.