Cobweb is a web crawler that can use resque to cluster crawls to quickly crawl extremely large sites which is much more performant than multi-threaded crawlers. It is also a standalone crawler that has a sophisticated statistics monitoring interface to monitor the progress of the crawls.

A UI for James Golick's rollout gem

A Ruby gem to verify the signature of Firebase ID Tokens. It uses Redis to store Google's x509 certificates and manage their expiration time, so you don't need to request Google's API in every execution and can access it as fast as reading from memory.

Ruby Adapter for Raygun

Open-source gems maintenance & maturity tracking

A nifty service layer for your Rails app

A simple API caching layer built on top of HTTParty and Redis

A simple API caching layer built on top of HTTParty and Redis

Related is a Redis-backed high performance distributed graph database.

Wraps memcached, redis(-namespace), memcache-client, dalli and handles their weirdnesses, including forking

Linearly scale Heroku dyno counts based on sampled metrics

initiate a M-Pesa transaction on behalf of a customer using STK Push.

Sidekiq agnostic enqueuing using Redis

A fair way to queue work in multi-user systems.

Management tool to make it easier rollouting features to customers.

GitLab metrics exporter to use with prometheus

istox backend shared gem

Pushr daemon for push notification services like APNS (iOS/Apple) and GCM (Android).

Fast and unobtrusive activity tracking of ActiveRecord models using DataMapper and Redis

Redisk includes Redisk::IO which is ~ Ruby's stdlib IO. It can be used with stdlib's Logger to log directly to redis