# Polyphony - Fine-Grained Concurrency for Ruby [DOCS](https://digital-fabric.github.io/polyphony/) | [EXAMPLES](examples) > Polyphony \| pəˈlɪf\(ə\)ni \| > 1. _Music_ the style of simultaneously combining a number of parts, each > forming an individual melody and harmonizing with each other. > 2. _Programming_ a Ruby gem for concurrent programming focusing on performance > and developer happiness. ## What is Polyphony Polyphony is a library for building concurrent applications in Ruby. Polyphony harnesses the power of [Ruby fibers](https://ruby-doc.org/core-2.5.1/Fiber.html) to provide a cooperative, sequential coroutine-based concurrency model. Under the hood, Polyphony uses [libev](https://github.com/enki/libev) as a high-performance event reactor that provides timers, I/O watchers and other asynchronous event primitives. ## Features * Co-operative scheduling of concurrent tasks using Ruby fibers. * High-performance event reactor for handling I/O events and timers. * Natural, sequential programming style that makes it easy to reason about concurrent code. * Abstractions and constructs for controlling the execution of concurrent code: supervisors, cancel scopes, throttling, resource pools etc. * Code can use native networking classes and libraries, growing support for third-party gems such as `pg` and `redis`. * Use stdlib classes such as `TCPServer`, `TCPSocket` and `OpenSSL::SSL::SSLSocket`. * Competitive performance and scalability characteristics, in terms of both throughput and memory consumption. ## Documentation The complete documentation for Polyphony could be found on the [Polyphony website](https://digital-fabric.github.io/polyphony). ## Contributing to Polyphony Issues and pull requests will be gladly accepted. Please use the [Polyphony git repository](https://github.com/digital-fabric/polyphony) as your primary point of departure for contributing.