Apple's Mac OS X 10.5 Leopard went on sale at the Apple Store in Tokyo on Friday evening, part of a global launch that will unfold around the world over the next 24 hours.

Apple is putting the software on sale at 6pm local time at stores worldwide. That means customers in Australia and New Zealand got a head start on the rest of the world, although Tokyo marks the first launch of the OS, also called Mac OS X 10.5, at an official Apple Store.

About 200 people queued in light rain in Tokyo's Ginza district for the start of sales, looking on as Apple staff prepared themselves for the event with cheers, countdowns and high-fives. The Apple store had been closed since 4pm to allow for the launch preparations.

At 6pm the first customers entered the store, already clutching T-shirts and a copy of the OS that Apple staff were handing out as they entered. Then it was off to the counter to pay.

Leopard is the fifth major upgrade that Apple has made to its OS, and its first in two-and-a-half years. The software will be installed on all new Apple computers, or cost £85 for an upgrade. Apple has said the vast majority of Macs sold over the past four years will be able to run Leopard, as well as some older machines, depending on their configuration.

The major advances include Time Machine, which automatically creates snapshots of the OS from an earlier point in time, allowing users to retrieve files and applications that have been deleted, or even earlier versions of documents that have been updated.

A feature called Spaces allows users to flick between a series of 'virtual monitors'. This allows busy desktops to be broken into several parts, and could make using a Mac easier for people who have a clutch of applications open at once.

Another new and welcome feature is Quick View, which allows users to preview documents without opening the relevant application. Word processor files, pictures, presentations and even movies can all be previewed right away.

There are also some cosmetic upgrades, such as a mirrored base on which the dock icons now sit. Other changes aim to better organize files: Downloads now all flow into a single folder, for example.

Apple is also releasing a server version of Leopard on Friday. Updates include an improved set-up process, a new version of the iChat Server software, and tools for hosting podcasts and wikis.

Leopard's launch continues today around the world. A French Apple dealer has promised a live leopard in a cage at one of its stores outside Paris.

(James Niccolai in Paris contributed to this report.)