1. Faster LEX. 2. A real-time language for dynamic environments. ["flex: Towards flexible Real-Time Programs", K. Lin et al, Computer Langs 16(1):65-79, Jan 1991]. 3. An early object-oriented language developed for the flex machine by Alan Kay in about 1967. The flex language was a simplification of Simula and a predecessor of Smalltalk. (1995-03-29)