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.

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

Hanami is a web framework for Ruby

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.

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

Routing tree web toolkit

Cuba is a microframework for web applications.

Cramp is a framework for developing asynchronous web applications.

Design-First Web Framework

The web app builder for Rails

Nothing to see yet.

Ramaze is a simple and modular web framework

Minimalist rack application interface building framework.

Harbor Framework

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.

Scalable Framework aimed at Speed and Simplicity

A bliki-type web content thing.

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.

New York, New York - a (ridiculously) small and powerful web framework.

Merb. Pocket rocket web framework.