Abstract. Modern Web applications are full-fledged, complex software systems. Therefore, the development of Web applications requires a methodologically sound engineering approach called Web Engineering. It is not clear, however, to which extent existing solutions from relevant areas, most notably software engineering can be reused as such for the development of Web applications and consequently, if Web Engineering is really a discipline on its own. This paper highlights the characteristics of Web application development as found in existing literature thus providing a prerequisite for analyzing the appropriateness of existing engineering solutions. The characteristics are categorized according to four dimensions, comprising the software product itself, its development, its use and evolution as a cross-cutting concern.