NeXTSTEP 1.0 Release

NeXTSTEP, the pioneering object-oriented operating system from NeXT Inc., was released. It featured a robust graphical user interface and a suite of innovative applications, including an early form of 'Address Book.'

Significance

This marked the first appearance of a highly advanced, integrated contact management application within a modern OS, laying the architectural groundwork for what would become Apple's Contacts.app.