Practical Common Lisp: Restarts and Generic Functions

HN remembers it as the memorable explanation of restarts and multiple dispatch, referenced whenever those features come up.

Peter Seibel's 2006 Google TechTalk on Practical Common Lisp, framed by the Sapir-Whorf hypothesis and Paul Graham's Blub paradox. It shows Lisp features such as condition restarts and its generic-function object system.