# Polyphony: Fine-Grained Concurrency for Ruby > 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 [io_uring](https://unixism.net/loti/what_is_io_uring.html) or [libev](https://github.com/enki/libev) to maximize I/O performance. ## 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. ## Installing ### System Requirements In order to use Polyphony you need to have: - Linux or MacOS (support for Windows will come at a later stage) - Ruby (MRI) 3.0 or newer ### Installing the Polyphony Gem Add this line to your application's Gemfile: ```ruby gem 'polyphony' ``` And then execute: ```bash $ bundle ``` Or install it yourself as: ```bash $ gem install polyphony ``` ## Usage - [Overview](docs/overview.md) - [Tutorial](docs/tutorial.md) - [FAQ](docs/faq.md) ## Technical Discussion - [Concurrency the Easy Way](docs/concurrency.md) - [How Fibers are Scheduled](docs/fiber-scheduling.md) - [Exception Handling](docs/exception-handling.md) - [Extending Polyphony](docs/extending.md) - [Polyphony's Design](docs/design-principles.md) ## Examples For examples of specific use cases you can consult the [bundled examples](https://github.com/digital-fabric/polyphony/tree/master/examples) in Polyphony's GitHub repository. ## 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.