raindrops is a real-time stats toolkit to show statistics for Rack HTTP servers. It is designed for preforking servers such as unicorn, but should support any Rack HTTP server on platforms supporting POSIX shared memory. It may also be used as a generic scoreboard for sharing atomic counters across multiple processes.

An easy to use ruby wrapper for Librato's Metrics API

Rack response-time statistics aggregator middleware

An easy to use ruby wrapper for the AppOptics API

Push reporting stats to Librato metrics

Flounder is the missing piece between the database and your Ruby code. It allows very simple access to database tables without going all the way to begin an object mapper.

Simple histograms using cane

A simple way to see what's up, dawg (and what's not.)