The course aims to present the principles that guide the web and make it so successful. It will begin by introducing the historical issues and the first attempts at similar systems. Then the architecture of the web will be detailed, including the multiple complementary standards and their roles in the big picture, but also including important proprietary back-end technologies like ASP. The students will learn good practices for web engineering, important mainly for accessibility and scalability of web applications. Finally, the course will introduce the topic of distributed applications on the web. Due to the similarity of intent with Web Services, special focus will be put on design issues and applicability of Web Services technologies.