"Well, not that much is different from how it used to be," he says, after a characteristic pause. "Two months before I left Finland [more than two years ago] we had our first child, and another 15 months ago. But as for my daily routine - well, I come in and sit in front of a computer and work on software. In that sense, my daily life hasn't changed much. And I'm still working on Linux."
Mr Torvalds, a boyish 28-year-old with mousy hair and big glasses, was born in Helsinki, though he lives and works in Santa Clara, in Silicon Valley, down the coast from San Francisco. He doesn't look the part of a world-dominating super-programmer, although he can spot flaws in huge swathes of computer code and fix them. Most of all, he knows the most abstruse things about the Linux operating system. He should. He wrote it, and still oversees its development. As for world domination - Linux could at least cripple, if not kill Microsoft, and halt its growing ubiquity on the world's computers.
Mr Torvalds calls it "Linnucks", articulated so quickly it's almost a single syllable, although almost everyone else says "Lie-nucks". It's a small difference, one of emphasis, and there are a few things to emphasise about Linux. It is an industrial-quality computer operating system (OS) that matches - and in some ways exceeds - Microsoft's products such as Windows95, Windows98, and WindowsNT. (Operating systems are software which essentially instruct the chip at the heart of every computer how to move data around and present it to the keyboard, monitor, hard drive and other input/output devices in a way meaningful to the user.)
Linux will run happily on a desktop PC (the original was written on one with four megabytes of memory, when that was a lot). It will also run on supercomputers with interlinked processors. Some say it's the best OS you can get for applications such as running big networks and web servers because of its "stability" - its ability to deal with multiple tasks and users without crashing. "Bugs" are ironed out in days, sometimes hours, of being made public. Yet Linux isn't any company's product. It is the co-operative result of hundreds (perhaps thousands) of programmers around the world adding their little bit of expertise to the original software Mr Torvalds released over the Internet in 1991.
And one other crucial thing: Linux is free. You can download it from the Net without charge. PC magazines have given away Linux on free, cover- mounted CDs. By contrast, Windows98 costs about pounds 50 (though the cost is usually subsumed into that of the PC it is found on). WindowsNT, for running large networks, will cost hundreds of pounds. Bugs are legion (and have delayed the newest version of WindowsNT - renamed Windows2000 - for two years).
So how much money has Mr Torvalds made out of Linux? "Nothing," he says. You can see how Linux might be a problem for Microsoft, which acknowledged the fact in its now-famous "Halloween letters", an obligatory filing to the Securities and Exchange Commission last October. These informed current and future shareholders that Linux posed a threat to its revenues in the WindowsNT market, which is where much of its future growth and revenue will have to come from. Last September, Steve Ballmer, Microsoft's president, told a conference that "free software is making inroads into the glass house. Are we worried about Linux? ... Sure we are worried". It was the first time Linux had received such recognition. Its bandwagon really started to roll. Since then, PC companies such as Compaq and Dell have begun offering PCs which have Linux, not Windows, installed. A small step for some computer companies, a big step in operating system strategy.
So how does Mr Torvalds see the "battle" between Microsoft's operating systems and Linux? There's a pause as he considers; Mr Torvalds has a reflective way of talking. Answers don't spill out, they are poured from a measured cup. You wouldn't come to Linus Torvalds for a snap decision, though you probably would for a rapid, well-thought-out one.
"To a large degree, most Linux work is done with absolutely no regard for Microsoft, because most of what comes out of Redmond [Microsoft's headquarters near Seattle in Washington state] isn't interesting. Personally, Linux was never about going up against Microsoft. It was just that their products weren't good enough."
That's true. Linux began when Mr Torvalds was 21, living with his parents and working at Helsinki University in Finland as a computer science teaching assistant. He wanted an operating system for his PC, which had an Intel 80386 chip (in 1991, the latest thing). Every OS has strengths and weaknesses. What Mr Torvalds desired was something "stable" - not like Windows, or MS-DOS (its predecessor). "You sit there hoping [they] won't crash. I really hate not being able to trust the system."
So he wrote his own, based on a small operating system intended as a teaching aide for how such things should work. This system was based on Unix, then 25 years old, and widely used in academia, but not available for Intel chips. Mr Torvalds wrote an "Intel Unix" that seemed to him to do the job - mostly. Then he made it available on the Internet, via a friend's computer, to see what other people thought of it. (The name "Linux" was his friend's suggestion, a marriage of "Linus" and "Unix"; Mr Torvalds had wanted to call it "Freix", for "free Unix".)
Along with the programs, he included the "source code", the equivalent of the software blueprint, and invited users to suggest improvements. They did. The changes got faster and faster. Linux got better and better. By early 1992 it had 100 users. Improvements were sent by e-mail, and the whole process enabled by the Internet. No money changed hands. It still doesn't. But sometime around 1992 the web happened, and the whole Internet thing happened. Linux took off with it.
But if Linux is free, and it is regarded as more stable and powerful than Windows, why isn't everybody using it? Actually, they might be, but you wouldn't know it: many Internet service providers use it to run their machines. There are probably nine million Linux users out there, and the number is growing.
But installing Linux is like being given a thoroughbred horse which has never been ridden. It has a lot of potential, and it could take you a long way very quickly. But to make the most of it you either need professional help, or you have to be very skilled yourself, in breaking that horse in. By comparison, Windows is a friendly horse down at the local stable - occasionally unpredictable, but generally safe, if slow and limited.
Thus, companies are springing up offering paid-for services to help install and tame Linux. The product is free but the service isn't, which is a feasible business model by any standards. (Remember Gillette and the free razor handle and expensive razor blades, one of the more successful business models.) The difference is that Linux was not planned as a business. It was planned as, and still is, just an operating system. But if it's so good, why give it away? "It's like infrastructure," says Mr Torvalds. "[Linux] doesn't do anything on its own." Which is true: what it does is make the computer ready to run other applications such as word processing, spreadsheets, databases, storing and showing web pages, and so on, tasks one thinks of as "computing".
That's why operating systems matter: they let you write programs you can really make money on. Windows brought riches not only to Microsoft, but perhaps to millions of people in thousands of software companies whose programs run on it. Linux, while being promising, doesn't yet have as many applications written for it. But many companies, including IBM and Lotus (its subsidiary), Oracle, Sybase and Corel are rewriting their programs so they can run on Linux. If you go to the Linux home page (at www.linux.org) there is a raft of applications - including word processors and spreadsheets - available for Linux. Most of them are not free. But that's not surprising.
Another question: Linux is free, yet clearly is the fruits of work by experienced programmers. So who is really paying for it? Grumpy IT managers complain it is their staff, working in company time on things to be used outside the company, in effect, a "leakage" of value from their company.
"Instead of one large company, you have lots of small leaks of time," says Mr Torvalds. "But that's a feature, not a problem. It's not one single big entity paying for the development, but lots of small ones. And if it works well, then there will be more money for them all. I don't see the economic side of Linux as a big fault. It's just different from what people are used to, that's all."
Why release the source code? "Because the software is so important to a lot of people, I want them to be able to test it. And I don't want anybody in particular to be able to control it. The reason is that in today's world if you control software, you have a lot of power. Taking that thought, it makes sense if everybody gets to put in a bit of effort."
Mr Torvalds has also neatly ensured that nobody can buy out Linux, by rigging the structure so that nobody - not even he - "owns" it. Every programmer who has contributed a change retains their copyright; but they have to agree to let that code be redistributed for free.
So has he really made no money out of Linux? "Nothing." Nothing at all? "No." Not, at least, in revenues from "sales" of Linux. But, in another sense, he has benefited hugely from it. At only 28, he is known throughout the computer world. More usefully, all that unpaid work has led to him having a well-paid job (how much is secret) working for Transmeta, a computer startup company. (What Transmeta is doing, and when it is going to announce it publicly, is also secret.)
"Transmeta came to me with an offer. I made sure that we moved closer to work than in Helsinki, so I would have a shorter commute time than in Finland. Most of the environment changes have been positive. I like the American mentality. People call it shallow, but I think it's different from Europe. Finns
are friendly but they're kind of silent, and they never contact you. If you're walking around in Helsinki nobody will talk to you unasked. Over here we walk around with the kids and people say, `What lovely children, how nice for you'. And of course the weather is nice here too."
Better, in fact, than up north in Redmond, where Microsoft's troops work on WindowsNT and its successors. Does he think Windows2000 (intended to run systems in large corporations, and due for release next year) has improved? "Not really," he told BootNet, an online programmers' magazine. "The develop- ment is done for the purpose of making money, rather than for solving technical issues." He is disparaging about many Redmond products. "Microsoft has been very much into making the user interface [what the user sees on the computer] look good, but internally it's a mess. Even people with years of experience who program for Microsoft don't know how it works internally."
The trouble is that the more complicated everything gets, the less you can rely on it - exactly the opposite of what you want in a computer. Mr Torvalds likes Linux's tidiness. He approves too of the development of "WINE" - a Windows Emulator for Linux, a program to let Linux users run Windows programs. Could he have written Linux had he lived and grown up in the US? "It would have been a lot harder, because it's much harder to study and to be freewheeling. But there's also the American mentality towards money. If I had grown up here, I would have taken a different approach to money - like, `Let's have a startup company for this operating system'. Living in Finland - like people in most of Europe - that wasn't my first thought."
The fact is that Linux is catching up with Microsoft. Bill Gates and Co know very well how free software can undermine market share - they were the ones who chopped the legs off Netscape's paid-for, market-dominating web browser by writing an inferior one, Internet Explorer, and giving it away free.
Netscape was forced into the arms of America On-Line last year. But that can't work on Linux - how do you undercut something that's free? And Microsoft can't use its other favoured tactic, of buying up a rival, because no one"owns" Linux.
So what's left for Microsoft? Not a lot, apart from the now-familiar lesson that the Internet changes everything, including software develop- ment. Because Mr Torvalds uses the Internet, everyone in the world can help develop on system. That means he can find the best programmers without getting them to move, because his development method is the ultimate in teleworking. Microsoft has to hire them, offering stock options, and persuade them to move to Redmond, where the weather is often more like Helsinki on a bad day than Santa Clara.
Some things are tougher about Santa Clara than Helsinki. Mr Torvalds' hours at Transmeta are longer than at university - 10 till 6, rather than 10 till 4.
"But we have more variety of life over here," he says. Ironically, seeking a system he wouldn't have to worry about, he produced something that will probably be with him for the rest of his life. If Linux survives that long, it'll probably delight him.