The World Wide Web, shortly named the web in the following context, is the most popular service on the Internet. At first, the web is just built for information exchange. As many web related technologies grow, we can communicate with each other, finish daily works and execute many other complicated applications on the web. The JavaScript is the main programming language and computational engine in the front end of the web. Originally, this scripting language is only for simple and small programs which provide more interactive interface for end users. But in the current decade, Ajax (Asynchronized JavaScript and XML) technology which is extended from JavaScript leads the web to the whole new world. Today, many large web applications based on Ajax technology are published. The most famous one of them is Google Online Office which has similar functions compared to traditional Microsoft Office but based on the web technologies. Because the web is not only the platform for information exchange but also the computational platform based on JavaScript engine, every computer having installed modern browser on the Internet can easily access the web and execute some JavaScript programs. Under above conditions, we develop a distributed computing system based on the web and JavaScript technologies. Our system plays an intermediary role between the IT expert who has to solve large-scale computational problem and end users on the Internet. In the other words, people could easily cooperate with each other to finish complicated computational problem through the support of our system.