This paper discusses the WebOS system based on the Ext framework and Cloud Computing, which achieves an powerful, flexible and high performance front-end UI System Framework and can be well extended by using Ext. It provide basic operating system services needed to build applications that are geographically distributed, highly available, incrementally scalable, and dynamically reconfigurable. The WebOS framework enables a new paradigm for Internet services. Instead of being fixed to a single location, services can dynamically push parts of their functionality out onto Internet computing resources, and even all the way to the client. In the developing process, development and design process of Web widget is practiced which is based on Microsoft's latest windows Azure cloud computing platform and web2.0 technology.