=CloudKit
CloudKit is an Open Web JSON Appliance.
More specifically, CloudKit provides RESTful JSON storage with optional OpenID and OAuth support, including OAuth 
Discovery. Stored entities are versioned. Services manage their own storage and do not require schema updates when 
models change.
CloudKit is Rack middleware and as such can be used on its own or alongside other Rack-based applications or middleware 
components like Rails, Merb or Sinatra.
===Install
  gem install cloudkit
===Examples
In a rackup file called config.ru:
  require 'cloudkit'
  expose :notes, :todos
The above creates a versioned HTTP service using JSON to represent two types of resource collections -- Notes and ToDos.
In a different rackup file:
  require 'cloudkit'
  contain :notes, :todos
The above provides the same API as example 1 with added authentication and authorization via OpenID and OAuth, 
respectively.
An explicit version of example 2, minus the default developer landing page:
  require 'cloudkit'
  use Rack::Pool::Session
  use CloudKit::OAuthFilter
  use CloudKit::OpenIDFilter
  use CloudKit::Service, :collections => [:notes, :todos]
  run lambda {|env| [200, {'Content-Type' => 'text/html', 'Content-Length' => '5'}, ['HELLO']]}
The same as above, using MySQL:
  require 'cloudkit'
  use Rack::Config do |env|
    env[CLOUDKIT_STORAGE_URI] = 'mysql://user:pass@localhost/cloudkit_example'
  end
  use Rack::Pool::Session
  use CloudKit::OAuthFilter
  use CloudKit::OpenIDFilter
  use CloudKit::Service, :collections => [:notes, :todos]
  run lambda {|env| [200, {'Content-Type' => 'text/html', 'Content-Length' => '5'}, ['HELLO']]}
See the examples directory for more.
===Online
Main Site: https://getcloudkit.com
Blog: https://blog.joncrosby.me
Google Group: https://groups.google.com/group/cloudkit
Source: https://github.com/jcrosby/cloudkit
===License
Copyright (c) 2008, 2009 Jon Crosby https://joncrosby.me
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.