help to kill N+1 queries and unused eager loading.

New Relic is a performance management system, developed by New Relic, Inc (http://www.newrelic.com). New Relic provides you with deep information about the performance of your web application as it runs in production. The New Relic Ruby agent is dual-purposed as a either a Gem or plugin, hosted on https://github.com/newrelic/newrelic-ruby-agent/

Provides a better error page for Rails and other Rack apps. Includes source code inspection, a live REPL and local/instance variable inspection for all stack frames.

FnordMetric is a Ruby Event-Tracking gem on steroids

Supporting gem for Rails Panel (Google Chrome extension for Rails development)

Take a peek into your Rails application.

Every Rails page has footnotes that gives information about your application and links back to your editor.

Monitors Ruby apps and reports detailed metrics on performance to Scout.

The exceptionally handsome dashboard framework for Rails.

N+1 auto-detection for Rails with zero false positives / false negatives

The official appsignal.com gem

Debugging toolbar for Rack applications implemented as middleware

Collect statistics about how your application is performing with ease. Export metrics to various monitoring systems.

An experimental metrics client.

Monitoring and instrumentation APIs

The friendly gem that instruments everything for you, like I would if I could.

Collect high level application performance metrics and forward them for analysis

Debugging toolbar for Rack applications implemented as middleware. Based on logical-insight and rack-bug.

Observe your web applications in the wild! == DESCRIPTION

Surface slow code paths in your Rails 3 app via Growl / libnotify

Automatic tracing and metrics for Ruby applications. Get started at appoptics.com. @AppOptics

The Rails View Annotator makes it easy to find out which partial generated which output