Web engineering is a new research line in software engineering that covers the definition of processes, techniques, and models suitable for Web environments in order to guarantee the quality of results. The research community is working in this area and, as a very recent line, they are assuming the Model-Driven paradigm to support and solve some classic problems detected in Web developments. However, there is a lack in Web requirements treatment. This paper presents a general vision of Navigational Development Techniques (NDT), which is an approach to deal with requirements in Web systems. It is based on conclusions obtained in several comparative studies and it tries to fill some gaps detected by the research community. This paper presents its scope, its most important contributions, and offers a global vision of its associated tool: NDT-Tool. Furthermore, it analyzes how Web Engineering can be applied in the enterprise environment. NDT is being applied in real projects and has been adopted by several companies as a requirements methodology. The approach offers a Web requirements solution based on a Model-Driven paradigm that follows the most accepted tendencies by Web engineering.