Rack::Stereoscope puts an HTML face on RESTful APIs.

Rack Rake middleware/app.

LTSV logger for Rack applications implemented as middleware

Rack middleware for checking if app is alive or not - optionally via custom condition(s).

It's a rack middleware to validate the header Content-Type of requests.

Racknga is a Rack middlewares that uses Rroonga features.

A Rack middleware for form-based authentication. It works roughly like Basic HTTP Authentication except that the authentication page can be styled with the middleware options.

Rack application, "RESTful" Rails style.

OAuth Echo authentication by a rack middleware

Rack middleware to automatically include Chartbeat embed codes in your site.

This Rack middleware component uses the CodeRay gem to automatically format code syntax by detecting a specific container in the final rendered markup.

redis session store for rack

Rack middleware for automatically cleaning markup using Tidy

Rack Middleware for OAuth Authorization and Authentication via/twitter

Rack middleware for generating xapfiles that know about the DLR

Rack middleware for using consistent time in request.

Rack middleware to rewrite the links on both the request and the response.

Rack middleware for stubbing responses from HTTP web services

Version your Rack based API's using headers either through middleware or routing constraints

Rack handler and other tools for communicating with a BRIDGE-capable server (like CloudBridge)