Somatsu is a web app with its Rack middleware permits to manage rails apps installationsadding multi database support.

A series of scripts and a rack application for backing up databases and filesystems into tarballs, encrypting, and then storing off-site on AmazonS3

A ready to use spine.js rack skeleton builder with development server, routes, config and precompile support

Rack middleware for the Stackprofiler profiling gem.

Staging rack application purpose to protect you Rails application from anonymous and prying.

This gem uses Rack middleware and the Rails 3 Notification API to display page load time and amount of queries executed.

Store ginormous files on S3 or the Rackspace Cloud using this gem.

A simple rack handler to allow to use suburis without using --prefix

A Rack app that responds to queries containing a country code with appropriate subdivision data as JSON.

Sunshine is a framework for rack and rails application deployment. This gem was made possible by the sponsoring of YP.com (http://yp.com).

Flexible Swagger documentation for Rack and Grape

Rack validation middleware using Swagger

Synapse is a web application framework that does practically nothing. Basically this is just a tiny wrapper for the Rack::Router (see http://github.com/carllerche/rack-router) very alpha-ish stuff here. Seems to work though.

Sworn is Rack middleware to handle OAuth 1.0a signed requests

Synfeld is a web application framework that does practically nothing. Synfeld is little more than a small wrapper for Rack::Mount (see http://github.com/josh/rack-mount). If you want a web framework that is mostly just going to serve up json blobs, and occasionally serve up some simple content (...

Rack middleware to communicate with a telegram bot.

a collection of test helpers for Ohm, Sinatra, Rack

Testify is a test framework framework. Think "Rack for testing."

texrack is a microservice that renders LaTeX as PNG files. Can be mounted in a Rack app

Easy way to deploy and monitor Rack applications as .rap archives