Software reuse is commonly achieved through extension mechanisms. Those mechanisms are practiced in software extension tasks. In these tasks, application developers retrieve code examples (step 1), acquire API documents (step 2), and adapt code examples (step 3). At step 2, they spend much time in manually searching API documents, confirming the valid API document version, and re-doing the searching work. At step 3, they spend much effort in frequently switching between web browsers and the local development environment, and rebuilding the development environment on different devices. To reduce the time and effort, a document link provision cloud, named dCloud, is provided in this work. dCloud reduces the time by only providing the document links and the link history. Such links are used to directly access the API documents of their valid version. dCloud reduces the effort by providing an online development environment which is accessed through web browsers. Furthermore, dCloud brings further advantages to application developers and makes a revolutionary impact on the development environment design.