theme_park is a flexible multiple theme plugin for rails3, sinatra, and more...it's rack based

A API Service for Wizard of Oz style testing.

Very lightweight web server for JRuby based on Netty library.

Rack middleware to convince thin-async and rack-test to play nicely.

Ruby on Thomler

A simple statsd middleware for rack.

Rack middleware for serving up RPC endpoints.

thrift http rakc server

A client/server implementation of THTP: Thrift-RPC over HTTP as a Rack app

Image server proxy that can resize images on the fly. Built in ruby as a Rack application.

Port of the sabre-http library to ruby. The tilia_http library provides utilities for dealing with http requests and responses.

Serve static files with rack and tilt

toto with textile (via RedCloth)

A tiny flash implementation for Rack apps

Tipsy is a mini Rack application for working with static websites using Tilt, and Sprockets.

Rack-based console inside your web applications - this is a fork of http://github.com/codegram/rack-webconsole

Multi-strategy feature flags.

Shotgun with default port of 4567. Everything else should be the same as rtomayko's shotgun

Send and receive events from remote services over HTTP.

An opinionated rack-based ruby lightweight framework