Monolithic operating systems consisting of "standard blocks" are on the way out, said Linus Torvalds yesterday, and they will be replaced by specially tailored and personalised systems. Torvalds was speaking at Internet World on the subject of Linux in business, and it appears he's now thinking about how the characteristics of open source software will give Linux an advantage over rival models. Open source allows rapid and varied development, and taking tow examples used by Torvalds yesterday, that means stripped-down versions can be produced quickly for, say set-top boxes, or at a more individual level companies can have their own tailored Web interface produced for their staff. As Linux was originally designed to run on pretty modest hardware anyway, it's also inherently easier to get it onto a diverse range of platforms, particularly because the vast majority of new (and high volume) platforms will be low resource. The contrast between this and the traditional/Microsoft model is pretty clear. The base OS is big, getting bigger, and isn't obviously or easily shrinkable to smaller platforms. In terms of branding at least Microsoft is getting away from one size fits all (more varieties of Win2k than you can shake a stick at), but each new platform size seems inevitably to lead to the development of a new OS. Developers don't have the ability to make changes to the code off their own bat, so tailoring for different classes of platform and customer tends to be bottlenecked in the Microsoft development process. You could say that Windows Everywhere means an ever-increasing number of different platforms designed and controlled by Microsoft, while Linux Everywhere just sort of grows, as a feature of the model. Linux Everywhere looks more do-able, and could be fed by exponential growth in developer effort. Torvalds also warned that open source does not automatically succeed, giving Mozilla as an example of one that went wrong, because Netscape failed to get enough outside momentum behind it. As far as 'sort of' open source models are concerned, he doesn't see either Microsoft's or Sun's approach cutting it. Microsoft actually hasn't gone much further than repeatedly saying it's thinking about opening up some of the NT code, and Torvalds doesn't believe that's going to happen anyway. He's critical of Sun's recently announced Community Source plan for Solaris, which he said leaves Sun in control, and won't work for that reason. ®