Ansible - Radically simple configuration-management, application deployment, task-execution, and multi-node orchestration engine
Speedcube - A simple and elegant Rubik's cube solve timer
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Linia - You will never look at colors the same way...
Puppet Enterprise - Get started with Puppet Enterprise, or upgrade or expand.
Colorcube - Turn pieces and blend colors in this minimal puzzler