Microsoft has launched the Developer Preview build of Windows 8 at its Build conference in Anaheim, California, and it's a radical redirection for the new version of the company's operating system. In addition, it revealed a host of new tools for developers to use to build new applications.

Windows Division president Steven Sinofsky also announced during his Keynote at the start of Build 2011, that all applications that work on Windows 7 will also work on Windows 8, as it has been built on the foundations of the current OS.

New features revealed in Windows 8 include a new Start Screen, which apes the user interface of Windows Phone 7 and the expected new UI of the Xbox 360. The lock screen will use things like touch sensitive photos rather than passwords and feature small icons detailing information like email, internet connectivity or battery life. 

Dubbed a Metro style interface, it's been specifically designed for touch based devices, hinting at the imminent announcement of a Windows 8 tablet, but can also be used with a mouse or keyboard.

It essentially puts social media content and applications into tiles that can be browsed before entering the PC's file system itself, offering a totally different aspect to Windows-based computing. And those apps will be able to communicate together, allowing software to suck pictures and content from social networking sites, for example. The home screen will also adopt a sort of Android style overview, where pinching will zoom out and show you each page of tiles running on your system. 

If you own other Windows-based devices (WP7 phone, for example), much of the content will sync across them all, and there will more integrated support for Sky Drive, Microsoft's cloud storage system.

The idea is to bring connectivity across all Windows devices and in particular the applications running on them. Rather than leaving applications themselves, content can be shared by swiping right and bringing up what Microsoft is calling 'charms'. Tap the share icon and then you can send whatever content you have selected to other apps running on the system without them needing to open an entirely new window. 

On top of this new cross-app interactivity, every single application will exist in two forms; a full screen and a docked view. The docked view allows you to essentially multitask, doing things like viewing Tweets on the left of the screen while reading a website on the right. It makes us think slightly of the QNX corner based operating system running on the BlackBerry PlayBook. 

Search is now heavily integrated into Windows 8. You can select to either search files, apps, settings or search via applications themselves. This means you can tap the search button and browse via Bing without leaving the actual search app itself or if you preferred, search Tweets through an inbuilt social networking app. 

Also announced is a new Windows Store which will offer app developers a shop window to hawk their wares. Naturally, Apple's Mac Store leaps to mind in this instance.

And, as expected, it has been revealed that Windows 8 will be universal and will work across a large number of platforms: "Support for ARM-based chipsets, x86 (as well as x32 and x64) devices, touch and sensors means Windows 8 works beautifully across a spectrum of devices, from 10-inch tablets and laptops to all-in-ones with 27-inch high-definition screens," says the company.

Developers will be able to download the Windows Developer Preview via the Windows Dev Center later this week, although no consumer release date has been mentioned as yet.

What do you think? Let us know in the comments below...