For Apple, the company Jobs co-founded and then left amid acrimonious disputes, his return as a special consultant could be either resurrection or apocalypse.

Shortly before Christmas last year, Apple shocked the industry by agreeing to buy Next Software ? the company that Jobs set up in 1985 after leaving Apple ? for $400m. Next produces the Unix-based Nextstep operating system which Apple plans to bring into the Mac fold.

It has long been accepted that Apple could not continue with its own plans for a new Mac OS. Its in-house project, Copland, was effectively shelved with the arrival last autumn of Ellen Hancock, the company?s new chief technology officer.

A former crony of Apple chief executive Gil Amelio from his days running National Semiconductor, Hancock brought a new ruthlessness to Apple, decreeing that the company?s development teams were too bogged down in internal politics, and slaughtering sacred cows in search of profitability.

Rhapsody, the codename for the new system based on Nextstep, has cross-platform capability, so it can run on the Intel platform, Risc chips and Sparc, which would broaden Apple?s potential customer base and encourage software developers to use it. Hancock has gone on record as saying: ?We are a systems company that is too much dominated by hardware? We are a strong component of PowerPC, but there is clearly a strong market on the Intel side.?

Jobs, meanwhile, has reappeared on the Mac scene like Moses arriving to guide his people back to the promised land, and was greeted by Apple staff with standing ovations. Although the journey ahead might make the parting of the Red Sea look like a walk in the park, Jobs himself has no doubts about the road in front. With characteristic chutzpah, he proclaimed at his welcome home press conference that ?much of the industry has lived off the Mac for over 10 years, slowly copying its revolutionary user interface?. He aims to bring the breath of revolution back to the company. ?Now the time has come for innovation, leapfrogging existing platforms and fuelling Apple and the industry copycats for the next 10 years and beyond.? Jobs said.

Whether the Mac can win back business from its main imitator, Windows, remains to be seen. Its traditional strongholds in the image-processing and desktop- publishing environments won?t be enough to keep Apple in the manner to which it has become accustomed.

Next could well push the company into more high-end markets, and even offer businesses a reliable and innovative platform for enterprise-wide computing. But how many businesses will be prepared to take the gamble, even if the promised new functionality is forthcoming?

There is a long way to go. Shortly after the Next announcement, Apple posted losses of $120m for its first quarter and now does not expect to make money until September. Unless the company can convince both existing users and businesses devoted to Wintel that the Next system is really going to work, that decline may prove irreversible and Jobs a false prophet. Diehard Apple users will certainly need to keep the faith.