Pow is a zero-config Rack server for Mac OS X. Have it serving your apps locally in under a minute.

All the benefits of a hand-crafted grid, without all the math.

The best way to manage Ruby applications

Jammit is an industrial strength asset packaging library for Rails, providing both the CSS and JavaScript concatenation and compression that you'd expect, as well as YUI Compressor and Closure Compiler compatibility, ahead-of-time gzipping, built-in JavaScript template support, and optional Data-URI / MHTML image and font embedding.

Riak combines a decentralized key-value store, a flexible map/reduce engine, and a friendly HTTP/JSON query interface to provide a database ideally suited for Web applications.

Fat Free CRM is open source Ruby on Rails-based customer relationship management platform. Out of the box it features group collaboration through task assignments, campaign and lead management, contact lists, and opportunity tracking.