Rational Software

Rational Machines is an enterprise founded by Paul Levy and Mike Devlin in 1981 to provide tools to expand the use of modern software engineering practices, particularly explicit modular architecture and iterative development. It changed its name in 1994 to Rational Software, and was sold for US$2.1 billion (equivalent to current US$3.48 billion^[1]) to IBM on February 21,^[2] 2003.

Rational Software

Industry	Application development tools
Founded	1981 (1981)
Founder	Paul Levy and Mike Devlin
Defunct	February 20, 2003 (2003-02-20)
Fate	Acquired by IBM
Key people	Mike Devlin (previous CEO)
Website	www.ibm.com/software/uk/rational/