Futuroscope is yet another simple gem that implements the Futures concurrency pattern.

Fibur is a gem that gives you full concurrency during your I/O calls in Ruby 1.9.

Wraps the net-snmp core usage into idiomatic ruby. It is designed to support as many environments and concurrency frameworks as possible.

Concurrently is a concurrency framework for Ruby and mruby based on fibers. With it code can be evaluated independently in its own execution context similar to a thread: hello = concurrently do wait 0.2 # seconds "hello" end world = concurrently do wait 0.1 # s...

A lightweight gem for foreign exchange and currency conversion.

A Redis-backed concurrency management system

Gqtp gem provides both GQTP client, GQTP server and GQTP proxy implementations. They provide asynchronous API. You can use gqtp gem for high concurrency use.

Actors based concurrency library for Ruby.

An ETL (Extract-Transform-Load) library that uses a forking process model for concurrency.

A concurrency library for Ruby inspired by java.util.concurrency and Go (golang). By http://www.appoxy.com

A Ruby web server designed to have a predictable and simple concurrency model, and to be capable of running in a pure-ruby environment.

An implementation of the CSP concurrency primitives

A bare-bones Ruby HTTP server that talks Rack and uses a thread per connection model of concurrency.

Retlang is a high performance C# threading library. The library is intended for use in message based concurrency similar to event based actors in Scala. The library does not provide remote messaging capabilities. It is designed specifically for high performance in-memory messaging.

Declarative concurrency for EventMachine

Some tools to make concurrency in Ruby, like thread pools

URL agent can handle common errors, concurrency and fallback for applications that call a large number of URLs.

FastFind is a high-performance Find alternative for Ruby implementations with effective thread concurrency, particularly JRuby.

Huginn (from Old Norse "thought") is a high-performance Ruby MQTT client written using an actor-based model. Its main goal is high concurrency and high performance.

Provides a foreign function interface for MRI that utilizes XAPI for Ruby implementations with modern garbage collection and concurrency facilities.