TEXT OF INTERVIEW

KAI RYSSDAL: Microsoft's new operating system is finally available to consumers today. Tonight, actually. The company's doing one of those midnight unveilings you usually see with a Harry Potter book.

People have been waiting a while. Depending on how you count it, Windows Vista is anywhere from two to four years late. Which has given Apple plenty of fodder for its ads:

PC: Well, I'm upgrading to Vista today, which is great, but I get a little nervous when they mess around with my insides.

MAC: Well what do you mean? Isn't it just straightforward?

PC: Not really. Like a lot of PCs, I have to update my graphics card, my memory, if I want the premium package, I need a faster processor . . . it's major surgery.

MAC: I'm . . . sorry about that.

PC: Listen, Mac. If I don't come back, I want you to have my peripherals.

But there's a case to be made that Vista's just about right on time. Software projects are notoriously late, and even when they're finished, they're not, really. Between updates and fixes.

Salon.com co-founder Scott Rosenberg's out with a new book on the perils of software programming. It's called "Dreaming in Code." And I asked him what took Microsoft so long.

SCOTT ROSENBERG: Everyone looked at all the projects that hadn't gotten into the last version of Windows and said, "What can we fit in? What can we do this time?" And at some point early on, there was this idea of being very ambitious. Of saying, Windows XP had been a small step. This time, let's really dig in. Let's solve the problems of Windows.

It became the kind of project that in the industry they call a "Boil the Ocean" project. Which, you know, basically means you're gonna take on everything at once. But you kind of need the discipline to address things incrementally and to take bites that are manageable. And eventually, after two years of kind of false starts, that's exactly what they did.

RYSSDAL: Microsoft is a multibillion-dollar company. It's got its systems on desktops literally all over the world. I mean, it's not a stretch to say that Bill Gates changed the world. But even a company like that, with all the power that it has, can't make the software run on time.

ROSENBERG: The root of it is that software is so hard to visualize and hard to get a handle on when you're working on it. It's very hard to measure. You know, there's a . . . sometimes people in the field try to measure it by lines of code, it's sort of like how many words have you written on an article. And the problem is that sometimes the best piece of code is one that uses very few lines to accomplish what it's trying to do. So it's very hard to measure progress, and so you find yourself sometimes circling. And before you know it, you know, six months have passed, a year has passed, and the schedule that you once sketched out is in the garbage.

RYSSDAL: We call these people programmers and engineers, but really, I mean it is at least as much an art as a science.

ROSENBERG: Absolutely. It's sort of a . . . it's almost like a bridge between art and science. It's something that is a kind of this imaginative thing. People who write software actually sit and write, and in that sense it's like writing a novel. But, it has this other condition: it has to work. And in that sense, of course, it's more like a science. So it has this unique in-between quality. And that's sometimes where the problems come in.

RYSSDAL: But that does point to the fact that really, Vista or any other software program, is never, ever done. Somebody's always gonna go back in and tweak this button or change that line, right?

ROSENBERG: That's right. It can be changed, and it will be changed, and you need to assume that it will be changed. That people will always be finding new things that they want to do with it, extensions that they're gonna wanna make. And of course, also, there's a business reason behind that: If you add things to the software, you can sell it to people again.

RYSSDAL: Since nobody was really surprised that Vista's late, do you think Microsoft has lost anything in business terms, as a result of this delay?

ROSENBERG: Well you know, people are still gonna be buying Windows. So I think, you know, Microsoft will continue to make lots of money from Windows. What they've lost more than revenue is momentum. Because in the time that Vista has been in progress, huge changes have taken place on the Web. And Google has arrived as this major force. People are doing more and more of their computing through the Web rather than on the desktop. And that is a major change that plenty of people at Microsoft are busy trying to figure out, you know, their part in. But the idea that the operating system alone is going to matter as much as it did, say, when Windows 95 came out, that day has kind of passed.

RYSSDAL: Scott Rosenberg is a co-founder of Salon.com. His book on why software is so darn hard to write is called "Dreaming in Code." Scott, thanks a lot.

ROSENBERG: Thank you.