Prior versions of consumer Mac OS had no pre-emptive multitasking and were otherwise far behind the game. After several failed internal projects Apple then bought out NeXT and used their NeXTSTEP/OPENSTEP operating system to build a new multitasking operating system based on a Unix core (Mach).

Earlier releases of Mac OS X betas (such as Rhapsody) used a variation of the old "Platinum" theme. The Public Beta introduced the new Aqua interface that is still in use today.

Here is the default desktop.

As we can see, the new Aqua interface now bundles with it some new eye-candy. Everything has a polished look to it. There are pinstripes in the background of the new Dock and in any open window.
There are a few differences from the final version of Mac OS X:

• The Apple menu is not actually a menu, and is located in the middle of the bar.
• There are no drive icons on the desktop.
• The Special menu is still present.

Overall, however, it looks much unlike previous versions and more like Mac OS X of today.

This new menu changes to the name of the currently open application. Note that it says Desktop and not Finder, like later versions.

This menu also contains many of the options later moved to the apple menu.

While the Public Beta does have a control panel, most of the applets are still separate and are only accessible through menus, as is typical for modern Linuxes.