Microsoft is due to release Windows Longhorn build 4051 to attendees of its Professional Developer Conference (PDC), which kicks off today, and immediately before this, build 4051 leaked. So did it jump or was it pushed?

Actually, that's not a question that's particularly worth pursuing directly. Microsoft builds leak regularly, Microsoft knows this, and Microsoft knows that the wider the distribution of the software, the faster it's going to spread all over the internet. So even if you reckon that leaking builds at this juncture in the development process are extremely helpful to Microsoft, it's entirely unnecessary to presume that anybody at Microsoft needs to throw a switch. All they have to do is sit back and let it happen.

Which is where it does start to get interesting, because if we presume that the level of concern within Microsoft about leaking builds is likely to be in direct proportion to the intensity of the company crackdown to suppress these builds, then we'll be able to measure this as the development process unfolds. Lots of enthusiasm, screenshots and fairly direct routes to illicit downloads means Microsoft doesn't care/ maybe likes the publicity, while barrages of take-downs and people skulking in increasingly dark corners mean the other. And bear in mind the crackdowns on WinXP leaks got increasingly heavy as RTM neared. So go figure.

But we digress towards conspiracy theory again, so we'll knock that off. Neowin has a selection of screenshots and discussion, and WinBeta has some more. FTP access to the build will now be making its traditional way through IRC channels, and some form of activation crack is claimed to exist. But leaked, genuine keys are likely to start escaping when Microsoft hands out the official version on Monday.

With goodies in the offing, the PDC itself is, naturally, sold out, and Microsoft has ecstatic groupies (many of whom seem to work for, er, Microsoft) feverishly talking it up. And blogs as a weapon of competitive advantage are also rearing their heads.*

In addition, Microsoft Developer Network (MSDN) subscribers will get 4051 in December, while it's been mooted that it will be made generally available for a small, unspecified fee during November. All this build-up, the widespread distribution, and the hype-hyping that will result from the widespread distribution takes us back to the first question - why should you bother deliberately leaking it, or being concerned about it leaking, if you're proposing to spend Q4 officially leaking/releasing it?

The timing is impressive for an alpha build of a product that is not scheduled to hit the streets for another two years, and which could quite easily stretch to three. Microsoft has been running widespread pre-release access programmes at 'nominal' fees for some time now, but generally uses late release candidates which are as near as dammit RTM builds, but alpha, two to three years off RTM, is surely a breakthrough.

Why, you might reasonably ask, is Microsoft doing this? Build 4051 is said to be extremely stable, but you'd expect this to be so if Microsoft is going to be giving it away like sweeties. Any suspicions you might have at the notion of stable alpha builds are amply justified, as 4051 is a special build that is missing, among other things, the Aero GUI. So it's actually a side road in the development process, intended to get the excitement going and to gauge reaction on a more widespread basis than is possible in the actual development process. Microsoft isn't seriously going to be wanting bug reports from this wider audience, but it will be interested in trying to figure out whether people are likely to be happy paying for what it's put in so far, whether they're going to want more, what they're likely to want, and so on.

And the company possibly wants to know whether it can build some kind of extended community on the basis of widespread, ultra-early access to software in development. That clearly can't be done via something like the pre-RTM one-shots it's released in the past, because these outlive their purpose alomsot immediately, just as soon as the real thing ships. But what do you do with a whole bunch of people running alpha software during the following years of development? Leave them stranded? Or ship them some more later, and try to build community? It'll be worth watching to see whether this turns out to be just the obvious, a shameless piece of marketing hype to occupy an excitement void, or something bigger. ®

* We're impressed by how the magic of hyperlinking blurs all sorts of information sources into a convincingly healthy PDCblog 'embrace and extend.' Go here, for example and you will arrive at a listing of perfectly respectable publication .Net Developers Journal. Click on one of the "recent posts on PDC Bloggers" and by gad sir, you get straight through to a perfectly respectable article in the aforementioned perfectly respectable publication. There is plenty more of this baffling stuff, and now we worry that all The Reg has to do is finish the RSS feed (soon, people, OK?) and carelessly accept an invitation to a major Microsoft event, and - pow - we'll have been assimilated by the Redmond BlogBorg. It's a terrifying thought...