Pistachio provides a simple HTTP long polling middleware for Rack which is backed by the Stash gem

A doorman for your Rack application. Checks if REMOTE_USER matches the subdomain. Requires some authentication means to set REMOTE_USER.

Minimal server for Rack apps based in EventMachine and http-parser

Pup is a rack based ruby web framework for developing web applications with ease

Pubsubstub can be added to a rack Application or deployed standalone. It uses Redis to do the Pub/Sub

Upload files to Rackspace Cloud or Amazon S3 by URL or file with automatic image resizing.

Rack middleware that writes the serial number of issued certs to a Redis database. Uses r509 and r509-ca-http

Sinatra札幌の2013年～2014年の活動を振り返ると、いろいろなものとSinatraを組み合わせたものがほとんどでした。そこで、Ruby/GTK2（GTK+）、Gosu（SDL）、Sinatra（Rack）を例として、GUIアプリケーション、ゲーム、Webアプリケーションを対比させてみたいと思います。

Test S3 integration locally. Originally created by Curtis Spencer, modified by Mario Visic at Envato.

Rack Server API

iPhone web apps in full screen mode wipe cookies when the browser closes. This gem uses javascript to store cookie data to local storage and restore from local storage on load

In case of nginx proxy, I wish to set SCRIPT_NAME to some value, but it sets HTTP_SCRIPT_NAME. So that, I'd like to adjust SCRIPT_NAME and PATH_INFO accordantly

A simple CMS system built on top of sinatra for lighweight but feature rich sites

Would be useful to enable OpenID authorisation with your Ruby/Rails-based blog, personal website or whatever.

Enable server sent events with rack middleware implemented over Faye and Broadcaster (Redis Pub/Sub)

A rack application daemon that creates an iCal subscription file from exchange calendars.

Implements a Linked Data Platform domain model, Rack middleware for server implementers, and a simple Sinatra-based server for RDF.rb

A bare-bones Ruby HTTP server that talks Rack and uses a thread per connection model of concurrency.

Redirect is a simple Ruby redirect DSL build on Rack. It's like a simple Ruby mod_rewrite, so you can write and test your redirects in Ruby.

Enables HTTP 402-based on-chain payments for APIs and services using the x402 open standard. Includes Rack server middleware, Faraday client middleware, and a facilitator API client.