Lisp was far more powerful and flexible than any other language of its day; in fact, it is still a better design than most languages of today, twenty-five years later. Lisp freed ITS's hackers to think in unusual and creative ways. It was a major factor in their successes, and remains one of hackerdom's favorite languages.

The Cathedral & the Bazaar: Musings on Linux and Open Source by an Accidental Revolutionary (ed. 2001)