Capistrano is a system built in Ruby to execute commands on many servers, in parallel via SSH. Config files, jobs, etc are written in Ruby.
A platform to manage cloud computing resources, deployments, and so on. Essentially a simplified front end for AWS as far as I can make out.
On premises cloud computing platform, with an open source angle. Don't fully understand it.
Puppet is a system to abstract system administrator tasks such as configuring web servers, deploying database servers, and so on. It provides an abstract language to specify configurations and then handles deployment for you.
Put simply, Puppet is a system for automating system administration tasks. It's a language to define services, nodes, dependencies, and so on. Then it handles the "realisation" or "execution" of those definitions across multiple platforms, etc.
Scripts to auto install node.js on Ubuntu. Includes a few handy dependencies, etc. Neat.