Thomas Robert Gruber (born 1959) is an American computer scientist, inventor, and entrepreneur with a focus on systems for knowledge sharing and collective intelligence. He did foundational work in ontology engineering and is well known for his definition of ontologies in the context of artificial intelligence. In 2007 Gruber co-founded Siri Inc., which created the Siri intelligent personal assistant and knowledge navigator. Siri Inc. was acquired by Apple in 2010, and Siri is now an integral part of iOS.