ExtJS是一个很优秀的Ajax框架，可以用来开发带有华丽外观的RIA(富客户端)的AJAX应用，使得我们的B/S应用更加具有活力及生命力。由于它是一个用javascr ipt编写，与后台技术无关的前端ajax框架。因此，可以把ExtJS用在.Net、Java、Php等各种开发语言开发的应用中-ExtJS is a very good Ajax fr a mework that can be used to develop with a gorgeous appearance of RIA (rich client) and AJAX applications, makes our B/S application more dynamic and vitality. Because it is a written with javascr ipt and ajax front-end back-end technology-independent fr a mework. Therefore, it can be used to ExtJS. Net, Java, Php and other application development language development