Abstract: With the introduction of the concept of cloud computing, many desktop applications have been migrated into the cloud. The desktop Integrated Development Environment (IDE) has become a hot topic in recent years. This paper introduces CEclipse which is an online integrated development environment. CEclipse encapsulates the functions of local IDE into Web services, and then uses the services composition technology to combine all the services to form the core functions of online IDE. Besides, CEclipse utilizes the program static analysis and program dynamic analysis technologies to handle with the specific security issues of online IDE. In order to fully take advantage of online IDE, CEclipse proposes to use the data mining technology to explore the development behavior of the programmers, and use the mining result to give instructions to the programmers in their development process. Finally, CEclipse makes use of single sign on technology to integrate the existing Web application into online IDE, and proposes a suite of approach to semi-automatically migrate the function of eclipse plugin to the online IDE, so that it can improve the expansibility of the online IDE.