A Resque plugin for ensuring only one instance of your job is running at a time.

The Toto site for DevOpsCasts

Effing package managers! Build packages for multiple platforms (deb, rpm, etc) with great ease and sanity.

Two or more jobs with the same lock cannot be processed simultaneously by multiple workers.

Metamarkets Druid Data Store

Cube: A system for time series visualization.

Rack-based interactive console (à la Rails console) for your web application's front-end