David Harel (Hebrew: דוד הראל; born 12 April 1950) is a computer scientist, currently serving as President of the Israel Academy of Sciences and Humanities.Harel is best known for his work on dynamic logic, computability, database theory, software engineering and modelling biological systems.Since the late 1990s he has concentrated on a scenario-based approach to programming such systems, launched by his co-invention (with W. Damm) of Live Sequence Charts.He has also worked on other diverse topics, such as graph layout, computer science education, biological modeling and the analysis and communication of odors.He has advocated building a full computer model of the Caenorhabditis elegans nematode, which was the first multicellular organism to have its genome completely sequenced.