Flexible authentication solution for Rails with Warden.

An example Rails 3 app with subdomains and authentication (using Devise). With a tutorial.

An on-the-fly processing/encoding framework written as a Rack application.

A tutorial on how to use Formtastic with Mongoid (instead of ActiveRecord)

Try MongoDB! A simple MongoDB shell with tutorial that runs in the web browser.

A port of CouchDB's Futon web interface to MongoDB

Delicious Aggregator

API wrapper for Twitter and Twitter Search API's

A Rails form builder plugin with semantically rich and accessible markup.

AASM - State machines for Ruby classes