From Foundations of Ajax 

  Server-Side Frameworks 

  CPAINT 
  Sourceforge.net / projects / cpaint / 

  Cross-Platform Asynchronous Interface Toolkit implements Ajax on the server side by returning either text or DOM document objects to the client to be manipulated with JavaScript. 
  Released under the GPL. 
  Supports only PHP and ASP. 

  Sajax 
  Www.modernmethod.com / sajax 

  Allows you to directly call server-side code from your JavaScript. Sajax supports a number of languages including Perl, Python, Ruby, and ASP (Java is not recently supported). 

  JSON / JSON-RPC 
  Www.crockford.com / JSON / index.html 

  JavaScript Object Notation (JSON) is a text format that can be used to exchange data much like XML does. Designed to be easy for humans to read and easy for machines to parse while using conventions familiar to the C family of languages. 
  JSON-RPC is a remote procedure call (RPC) protocol, like XML-RPC, for the JSON language. 

  Direct Web Remoting 
  Getahead.ltd.uk / dwr / index 

  Allow you to call Java methods from JavaScript as if they were local to the browser. Though limited strictly to a Java backend, DWR is one of the more popular frameworks. 
  DWR fits into common Web frameworks such as Struts and Tapestry and is released under the Apache license. 

  SWATO 
  Https: / / swato.dev.java.net / doc / html / 

  Shift Web Applications TO (SWATO) is another Java-based Ajax framework solution. Work in any Servlet 2.3 or higher container and, like DWR, requires some configuration file updates. Utilize JSON to marshal data between the client and server and allows you to call server-side Java from a browser. 

  Java BluePrints 
  Www.java.net 

  The Solutions Catalog includes good documentation on using Basic Ajax, implementing autocomplete, creating a progress bar, and validating forms. It also includes JavaServer Faces components. 

  Ajax.Net 
  Ajax.net 

  Allow you to call. NET methods from a JavaScript client. Involve a single DLL that can be used with either VB. NET or C #. 

  Microsoft's Project Atlas 
  Http://atlas.asp.net/Default.aspx?tabid=47 

  Microsoft is focusing on making things easier for developers by providing a more robust development environment. Microsoft wants to deliver quite a bit, including a client-side scripting framework, ASP.NET controls, and Web Service integration. 

  Ruby on Rails 
  Www.rubyonrails.org 

  Allow rapid development of Web-based applications. 
  While developing Basecamp, the team at 37signals pulled out a framework called Rails. 
  Basecamp is a prime example of an Ajax application.