Ending years of waiting, the international rollout of Mac OS X began on Friday evening with special in-store events at resellers worldwide.

OS X is finally available for £99 from both the Apple Store and resellers.

"Mac OS X is the most important software from Apple since the original Macintosh operating system in 1984 that revolutionized the entire industry," said Apple CEO Steve Jobs. "We can't wait for Mac users around the globe to experience its stability, power and elegance."

Apple UK celebrated the launch with a party at UK reseller, Micro Anvika that began at 11pm on Friday, 23 March. Around 500 Macintosh users queued (see images) to enjoy guided tours of the OS, and for demonstrations from applications publishers Corel, FileMaker, Alias|Wavefront and Connectix.

Micro Anvika sold over 200 copies of the OS during the night, with a further 350 copies changing hands the following day. For a detailed report of users' impressions, hopes and concerns for the OS read our OS X vox pop

Mac OS X is built on a Unix-based foundation called Darwin. It's a robust OS, featuring true memory-protection, pre-emptive multitasking and symmetric multiprocessing on multiprocessor Macs. It offers a powerful graphics engine (Quartz), and implements advanced-PDF standards support. OpenGL and QuickTime 5 are also integrated within the OS, and its features are accessed through a new user interface, called Aqua.

Other features include dynamic-memory management and enhanced power management, meaning PowerBooks and iBooks will boot-up from sleep instantly, and that applications will be given exactly the memory they need to execute commands.

Networking is a breeze, too - OS X can get the Mac onto the Internet through any available network connection with no need to adjust settings. It also integrates powerful Web-development technologies and Java 2 support.

Apple is making frequent updates to its Web site as third-party applications and peripherals manufacturers announce their solutions for the new OS. Macworld will keep you up to date on any developers.