Strano allows you to run any capistrano task via a clean and simple web interface. Simply create a project from any of your Github repositories, and Strano will use the Capistrano configuration within the repository itself. Which means you don't have to set up Capistrano twice, and you can still run capistrano tasks from the command line without fear of different configurations being used, causing conflicted deploys.

Deployments are grouped by "stacks". You might have a "web" and "search" stack.

Each of those stacks might have different deployment environments, such as "staging" or "production".

A very opinionated deployment tool, designed to be as fast as technologically possible. (For more background, read the WHY.txt file) Should work with any project which is git hosted, not just Ruby / Ruby on Rails projects. Allows for local deploys as well as remote.

Keep track of service error rates using redis. Degrade functionality if they're too high

Conditionally roll out features with redis.

The rubber plugin enables relatively complex multi-instance deployments of RubyOnRails applications to Amazon’s Elastic Compute Cloud (EC2).

Rawr, a packaging and deployment tool, is all you'll ever need for your JRuby projects. With Rawr, a simple, pre-generated configuration file turns your code into an executable jar, a .exe for Windows, and a .app for OS X.

ChocTop packages and deploys any Cocoa application in a custom DMG, with generated Sparkle XML support.

God is an easy to configure, easy to extend monitoring library written in Ruby.