Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments. Genera is also sold by Symbolics as Open Genera, which runs Genera on computers based on an Alpha processor using Tru64 UNIX. It is available as proprietary software.