Apple announced yesterday that it has completed work on Mac OS X and sent it for production.

As promised, the £99 Mac OS X will ship on March 24. The OS will be available from the Apple Store and Apple resellers.

Mac OS X is built on an open-source, Unix-based foundation called Darwin and features memory protection, pre-emptive multi-tasking and symmetric multiprocessing when running on the dual-processor Power Mac G4.

New features It includes Apple's new Quartz 2D graphics engine, OpenGL for 3D graphics and gaming and QuickTime for streaming audio and video.

Apple's "21st century" operating system also features a new user interface called Aqua, which provides ease of use and greater functionality.

The OS will be available from the Apple Store and Apple resellers on March 24.

Because of time differences, OS X will go on sale first in the Cook Islands, New Zealand and Australia. These locations receive the OS the day before the US. Like the UK, Australian and New Zealand Macintosh users utilize Apple's International-English OS.

It is thought there are in the region of 24 million Mac users globally. Following the announcement that the OS has reached production, Apple's shares dropped slightly on Wall Street.