Publication of 'Design Patterns' (GoF)

The seminal book 'Design Patterns: Elements of Reusable Object-Oriented Software' by the 'Gang of Four' (Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides) introduced the concept of design patterns to a wide audience.

Significance

This book popularized the idea of formally cataloging reusable solutions to common software design problems, creating a common language and methodology that later enabled the formalization of patterns like DAO.