Interlisp (also seen with a variety of capitalizations) is a programming environment built around a version of the programming language Lisp. Interlisp development began in 1966 at Bolt, Beranek and Newman (renamed BBN Technologies) in Cambridge, Massachusetts with Lisp implemented for the Digital Equipment Corporation (DEC) PDP-1 computer by Danny Bobrow and D. L. Murphy. In 1970, Alice K. Hartley implemented BBN LISP, which ran on PDP-10 machines running the operating system TENEX (renamed TOPS-20). In 1973, when Danny Bobrow, Warren Teitelman and Ronald Kaplan moved from BBN to the Xerox Palo Alto Research Center (PARC), it was renamed Interlisp. Interlisp became a popular Lisp development tool for artificial intelligence (AI) researchers at Stanford University and elsewhere in the community of the Defense Advanced Research Projects Agency (DARPA). Interlisp was notable for integrating interactive development tools into an integrated development environment (IDE), such as a debugger, an automatic correction tool for simple errors (via do what I mean (DWIM) software design), and analysis tools.