Interlisp

Interlisp was a Lisp programming language environment developed primarily at Bolt, Beranek and Newman (BBN) and Xerox PARC in the 1970s. It was known for its highly interactive and user-friendly development environment, which significantly influenced subsequent IDEs.

Key features of Interlisp included:

• Automatic Error Correction: Interlisp was notable for its sophisticated error handling capabilities, including automatic error correction suggestions. It attempted to understand the programmer's intent and propose fixes for syntax and runtime errors. This dramatically reduced debugging time.

• DWIM (Do What I Mean): A core philosophy of Interlisp was "Do What I Mean," reflected in its attempt to anticipate and correct common programming mistakes automatically. This extended beyond error correction and into areas like code completion and default argument handling.

• Comprehensive Debugging Tools: Interlisp provided a range of debugging tools, including break points, single-stepping, and inspection of the call stack and variable values. These tools were tightly integrated with the editor and runtime environment.

• Persistent Storage: Interlisp systems typically supported persistent storage of the entire programming environment, allowing developers to save and restore their work seamlessly.

• Integrated Editor: The Interlisp environment included a powerful and tightly integrated text editor, often considered one of the most advanced editors of its time.

• History System: Interlisp maintained a detailed history of user interactions, allowing developers to undo actions, replay commands, and analyze their workflow.

Interlisp was influential in shaping the development of future programming environments, particularly those emphasizing interactivity and user assistance. While Interlisp is no longer widely used, its innovations continue to inspire modern IDEs and programming language design.