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

An in-development web framework using Rack.

Rack middleware that filters out the browsers your app doesn't support.

Warbler is a gem to make a Java jar or war file out of any Ruby, Rails, Merb, or Rack application. Warbler provides a minimal, flexible, Ruby-like way to bundle up all of your application files for deployment to a Java environment.

Restricts your Rails app to only provide requests during business hours using a Rack middleware

Minimum rack middleware for coverage

Generate your own shiny OpenAPI 3.0.0 documentation from Rspec request specs

Provides object geocoding (by street or IP address), reverse geocoding (coordinates to street address), distance queries for ActiveRecord and Mongoid, result caching, and more. Designed for Rails but works with Sinatra and other Rack frameworks too. (clone of Geocode for older rails/ruby versions)

Framework-agnostic Rack middleware that normalizes forwarded tokens, enforces trust boundaries, and checks header/claims consistency before verikloak.

This gem is almost a straight copy and paste of https://github.com/rswag/rswag/tree/master/rswag-specs with the Rails specific code stripped out so it can be used in Rack applications that don't use Rails.

kcar features an HTTP parser that will convert a bytestream into a 3-element array suitable for use as a Rack response. It is IO interface agnostic, so it may be used with HTTP streams over Unix domain sockets, regular files, FIFOs, StringIOs as well as traditional TCP sockets.

RapiTapir is a Ruby library inspired by Scala's Tapir for building type-safe HTTP APIs. It provides declarative endpoint definitions, automatic OpenAPI documentation generation, client code generation, and seamless integration with Sinatra, Rails, and Rack applications.

Rack middleware to detect and provide more detail on the requesting user agent edit

Rack metal with a better interface

A rack middleware for collecting JavaScript code coverages.

Sessionography has only one function: to replace Sinatra's session methods with a basic hash that persists across requests. Bypassing Rack::Session removes nearly all the complexity of unit and integration testing with session data.

For use with Rails and the RequestId gem, this sets the request id so it can be sent on to internal http services.

Obscenity is a profanity filter gem for Ruby, Rails (through ActiveModel), and Rack middleware.

Scrap is a Rack endpoint designed to expose various garbage and memory-related metrics about your app. Intended for tracking down memory leaks and bloat.

Blackbeard is a Redis backed metrics collection system with a Rack dashboard. It dreams of being a replacement for rollout and split, but is early in its development.