Two moments in Linux's shift to mainstream corporate operating system stand out.

The first was when a senior Intel figure joined Linux's progenitor Mr Linus Torvalds on stage at Internet World in San Jose in 1997, to announce Intel would invest in Linux distributor Red Hat.

Intel, Microsoft's longtime partner, was to take a stake in an operating system Microsoft fobbed off as unviable, but privately recognised as a threat.

The second moment was in 2000, when IBM said it was launching a Linux strategy. This was a marriage between computerdom's upper class and a street-smart, working class kid. Dr Hans Ulrich Maerki, chairman of IBM EMEA says: "Two years ago we concluded that this industry can't go on the way it did the last eight to 10 years, unless it makes some substantial moves in the direction of standards."

Customers don't want lots of costly, proprietary operating systems from numerous companies, he says. Because Linux is open source, the code within it is available to all. That makes it easy to build add-on programs, and for big organisations that typically have several "legacy" computer systems holding crucial data to link their systems together. Its only choice otherwise is to try to connect systems through complex "middleware" programs.

IBM is working towards a future of computing that interlinks computing systems not just within organisations but across the globe, in large, powerful "grids". IBM is thinking about computing power as a utility, like electricity or water.

The communal nature of the open source developer community means no corporate battles over getting their pet technology included in the standard. Development can be streamlined. That's given Linux "a higher growth rate than anything else", says Dr Maerki. On the other hand, he accepts IBM also has a large hardware and software applications business, both of which can cater to a market asking for Linux as the operating system.

IBM learned, by its near demise a decade ago, that it should no longer assume its own dominance and just tell customers what they want. "If you can't bring the right software and hardware to the customer, then you won't have a long-term relationship with the customer."

By throwing its backing behind Linux, IBM has given what was once seen as a funky geek OS, mainstream sparkle, mainstream support, which is what the corporate sector really wants.