Automated reasoning is becoming an essential issue in many Web systems and applications, especially in emerging Semantic Web applications. This article first discusses reasons for this evolution. Then, it presents research issues currently investigated towards automated reasoning on the Web and it introduces into selected applications demonstrating the practical impact of the approach. Finally, it introduces a research endeavor called REWERSE (cf. http://rewerse.net) recently launched by the authors of this article which is concerned with developing automated reasoning methods and tools for the Web as well as demonstrator applications. "For the semantic web to function, computers must have access to [...] sets of inference rules that they can use to conduct automated reasoning." Tim Berners-Lee, James Hendler, and Ora Lassila. The Semantic Web, Scientific American, May 2001