Early adopters had to turn to open source or shareware alternatives, giving rise to an active homebrew software community around the new operating system. Native shrinkware applications were few and far between. Also included with the Public Beta, but not in any subsequent versions of Mac OS X, were a simple MP3 player ( iTunes had not yet been introduced), Sketch, a basic vector drawing program demonstrating features of Quartz, and HTMLEdit, a WYSIWYG HTML editor inherited from WebObjects. The Public Beta included many of the standard programs bundled with macOS for decades to come, such as TextEdit, Preview, Mail, QuickTime Player and Terminal. To illustrate the benefits of the latter, at the MacWorld Expo in June 2000, Apple CEO Steve Jobs demonstrated Bomb.app, a test application intended to crash. The beta's arrival marked some fundamental technical changes, most courtesy of an open source Darwin 1.2.1 core, including two features that Mac users and developers had been anticipating for almost a decade: preemptive multitasking and protected memory. System icons were much larger and more detailed, and new interface eye candy was prevalent. Fundamental user interface changes were revealed with respect to fonts, the Dock, the menu bar (with an Apple logo at the center that was later repositioned to the left of the menu bar and made an active interface element). The Public Beta introduced the Aqua user interface to the world. The Public Beta succeeded Mac OS X Server 1.0, the first public release of Apple's new NeXT OPENSTEP-based operating system, which used a variant of the classic Mac OS's 'Platinum' user interface look and feel.

Mac os x 10.0 developer preview