Puppet lets you centrally manage every important aspect of your system using a cross-platform specification language that manages all the separate elements normally aggregated in different files, including users, cron jobs, and hosts, along with obviously discrete elements like packages, services, and files. Its simple declarative specification language provides powerful classing abilities for drawing out the similarities between hosts while allowing them to be as specific as necessary, and it handles dependency and prerequisite relationships between objects clearly and explicitly.
The Marionette Collective (mcollective) is a framework to build server orchestration or parallel job execution systems. It uses modern technologies and concepts that make it ideal for large and cloud-based infrastructures. It's specifically geared towards systems administration tasks, but can be seen as a generic framework too.
BitNami RubyStack provides a fast, easy way to develop and deploy Ruby on Rails applications. It includes Ruby, Subversion, MySQL, SQLite, ImageMagick, and several Ruby Gems, and will optionally install Apache 2.2 with rewrite and proxy support. It supports Windows, Linux, and OS X, so you can share the same Rails environment on multiple platforms.
OpenNebula is a toolkit to easily build any type of cloud: private, public, and hybrid. OpenNebula has been designed to be integrated with any networking and storage solution and so to fit into any existing data center. OpenNebula orchestrates storage, network, and virtualization technologies to enable the dynamic placement of multi-tier services (groups of interconnected virtual machines) on distributed infrastructures, combining both data center resources and remote cloud resources, according to allocation policies.
iExploder is like a fire hydrant full of bad HTML and CSS code to test the stability and security of Web browsers. It is available as a standalone Web server or CGI script. It continuously feeds browsers bad data in the hope that they will eventually crash. It is designed to run for hours, or even days until the browser crashes.
BitNami Tracks Stack is an all-in-one cross-platform installer for Tracks, a Web-based application to help you implement David Allen's Getting Things Done methodology. It installs Tracks, Ruby On Rails, and everything else necessary to have a running program in minutes. It works on Windows, Linux, and OS X.
EC2Dream Fogviz is a visual tool for building and managing cloud servers. It combines Fog, Ruby, and Chef into a tool that is particularly helpful when developing and testing Chef automation scripts. It currently supports Amazon AWS, Eucalyptus Cloud, and CloudStack including VPC, autoscaling, and the ability to list most entities., and Openstack clouds: Rackspace, HP Cloud, and CloudFoundry Open Platform.