Technofile: This Friday hordes of eager Mac fans will be queuing, come rain or shine, for the release of Apple's new operating system, code-named Tiger. But is it a new system, or just the old one with a few bells and whistles?

First, a little reality check. Since Steve Jobs returned to head the computer maker, Apple has turned launching a new product into an art form. Iron-clad secrecy in the lead-up to any launch clouds the product in a fug of hype and media interest, until finally, when the thing appears, the Apple faithful turn into gibbering sale-day shoppers and snap up whatever it is - iPods, software, anything.

That's not to say that Apple doesn't make several cool products, but a pinch of salt never hurts in this context.

Apple's new Mac OS X 10.4, or Tiger to its friends, has been promoted more than the average Apple product. It promises more than 200 new features, and hits the market "long before Longhorn" (the next Windows), as Steve Jobs, is fond of saying.

As with all previous versions of Mac OS X, at its heart is Unix, a very stable and very secure operating system developed at the beginning of the computer industry. Unix is partly the reason why Macs have almost no viruses compared to Windows machines.

With Tiger, Mac users will get a 64-bit system for the first time. In plain English, this does not mean it will run twice as fast as the current 32-bit system. Memory-hungry applications like databases should benefit. But 64-bit lays down a solid foundation for the next generation of computing.

The two big new features Tiger promises are Spotlight and Dashboard. Spotlight is a new way of searching your hard disk that will probably totally change the way Mac users interact with the system, and for the better.

Now, instead of having to work through the finder to find a folder or file, you simply type the search into Spotlight and up comes everything relevant, right from the moment you start typing.

Not only that but Spotlight will index literally everything, so any e-mail, image, PDF, file, or folder relevant to the search will appear. Mac aficionados will note that this function is very similar to some third-party software called Quicksilver, but Spotlight promises to be more powerful.

Next up is Dashboard. This is essentially a bunch of 14 everyday applications that appear on your desktop when needed, like a currency converter, a dictionary, a weather-checker and a calculator.

But because they are actually little implementations of old-fashioned HTML, they can also hold live data like flight information or breaking news. Anyone will be able to create a widget, and Apple hopes hundreds of these useful morsels will be created by other developers.

A new feature called Automator is a user-friendly way of making your Mac perform a repetitive task, like changing the title on 100 digital photos, or reformating 50 Word documents as text files. Macs have always had the AppleScript language to do this - now Automator opens this power up to anyone to simply click a button and sit back while the Mac does all the hard work automatically.

Apple has also embedded support for new technologies like the latest version of MPEG technology called High Definition H.264. This means broadcast-quality video on your desktop. Meanwhile Core Image is a technology that printers and graphic designers will love, rendering better on-screen images and boosting and extending the Mac's formidable graphics capabilities.

With Tiger, Apple has also improved its compatibility with Windows networks, which was already pretty good.

For the hyper-connected, Apple's instant messaging client, iChat, now becomes a surrogate video conferencing application, allowing a full-screen video conference between four people.

Apple's proprietary Web browser, Safari, now gets better support for the new-fangled RSS news feeds everyone is talking about. And Mail, Apple's e-mail client, is now looking more like a professional package than before. Be warned, however. Although Apple says Tiger will work fine on older Macs, some of the fancy graphics tricks may run best only on newer machines. As always, get as much RAM as you can afford.

All in all, is it worth filling you Mac tank with Tiger? It's the best Mac OS yet and is a worthy adversary for Windows XP.

Although Apple says this is a major release, in fact, Spotlight and Dashboard are the only two properly new features. Of these it is Spotlight that will probably improve your Mac experience the most, and, even on its own, is worth upgrading to Tiger for. Only those who always know where to find all their documents and e-mails on their hard disk (and I know I don't) needn't bother with Tiger.

Mac users will concur with Apple when it says Tiger is the first operating system to "get out of the way" and let you get your job done. And, unlike the next version of Windows, which is two years away, it's out today.