- visage 386 Graph collectd metrics in the browser, backed by a JSON API
- cucumber-nagios 265 Systems testing plugin for Nagios with Cucumber + Webrat + Mechanize + Net::SSH
- collectd-opentsdb 23 collectd writer plugin for OpenTSDB
- rails-puppet-quickstart 15 to kickstart getting your Rails app up and running ASAP
- errand 14 Errand provides Ruby bindings for RRD functions (via librrd), and a clear API for interacting with RRDs.