Ruby on Rails is a full-stack web framework optimized for programmer happiness and sustainable productivity. It encourages beautiful code by favoring convention over configuration.

Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call.

Sinatra is a DSL for quickly creating web applications in Ruby with minimal effort.

Hanami is a web framework for Ruby

The Godfather of Sinatra provides a full-stack agnostic framework on top of Sinatra

Routing tree web toolkit

Cramp is a framework for developing asynchronous web applications.

Cuba is a microframework for web applications.

Design-First Web Framework

Minimalist rack application interface building framework.

Ramaze is a simple and modular web framework

Nothing to see yet.

The web app builder for Rails

A light-weight Sinatra-inspired web framework for web sites and applications of any size.

The Plezi.io Ruby Framework for real time web applications.

Rango is ultralightweight, ultracustomizable, ultracool web framework deeply inspired by Django.

Async framework for writing API servers

A bliki-type web content thing.

Scalable Framework aimed at Speed and Simplicity

Harbor Framework

Marley is a framework for quickly building RESTful web services and applications. Development is fast for two reasons: Marley implements lots of sensible defaults, all of which can be overridden and most of which can be overridden easily. And Marley servers exchange only data and metadata with clients.

Merb. Pocket rocket web framework.

Strelka is a framework for creating and deploying Mongrel2 web applications in Ruby.