There is a new version of Windows available today: Windows 8. Every time you hear about Windows 8, you hear about how vastly different it is from Windows 7 and its predecessors. Then you head to a Microsoft Store, or stumble into one of those pop-up Microsoft Stores at your local mall, and you see the Microsoft Surface tablet… also wildly different from your Windows laptop or iPad. Or maybe you saw the Surface on TV. Sooner or later, you’ll hear or read about the operating system on the Surface: Windows RT.

What the heck is Windows RT?

If you’ve been following all the Microsoft news, Surface news, Windows 8 news and such, this blog post is not for you. If you still don’t know how Windows RT is different than Windows 8, you can read the boring corporate FAQ from Microsoft, or you can keep reading.

Windows RT is a Flavor of Windows 8

Windows 8 follows in the footsteps of Windows 7 and the versions that preceded it. It has the traditional desktop look & feel, it should run every single one of the apps you have on Windows 7, it runs on desktops, laptops, notebooks, netbooks, ultrabooks, hybrids, and tablets. You will primarily use a keyboard and mouse to use it, but it also works very well with touch screens. It has some cool new features, it’s crazy fast, boots in seconds instead of minutes, syncs your files & settings in SkyDrive automatically, and much more. Since it requires far fewer system resources than Windows 7, virtually every Windows 7 or Vista computer can run Windows 8, and even some Windows XP systems will be upgradeable. If you have Windows 7 today, an upgrade to Windows 8 is actually well worth it, especially since it’s so cheap.

Windows 8 comes in different flavors:

• Windows 8
• Windows 8 Pro
• Windows 8 Enterprise
• Windows RT

Windows 8 is the default edition most home users will get. Windows 8 Pro is the typical edition you’ll find on work & business PCs and laptops. The Pro edition provides more features corporations care about, like data protection, extra security, remote desktop, joining domains and such. The Enterprise edition is virtually the same as Pro, but it comes with a few enterprise-specific extras, and is only available via volume licensing (i.e. you can’t buy it at Best Buy or on Amazon). You can see a side-by-side comparison of the Windows editions in this Microsoft product page.

Before I dive into what Windows RT really is, it’s important that I clarify some key differences between Windows 8 and Windows 7.

Windows 8: Where is the Start Button???

Yes, you might have heard (or noticed) by now: the Start button, the one we’ve had in the lower-left corner of our Windows screens since Windows 95, is now gone. Removed. Fired. Axed. The Start menu has been replaced by the Start screen:

The Start Menu was basically only a launcher, a way to start your apps. You’d see a list of application shortcuts, grouped by folders, giving you access to your recent documents, the Control Panel, pinned applications, and you’d be able to search for stuff, from documents to programs and the Web.

The new Start Screen in Windows 8 also acts as a launcher. Every tile on the screen is actually a shortcut to an app, but it does so much more. These tiles are Live Tiles. They are part of the Metro Design Language by Microsoft (yes, I know, I called it Metro, until they have a really good name, I’ll keep calling it Metro), and were introduced in the Windows Phone 7 Start screen in 2010.

Live Tiles can receive application updates and notifications, showing you the data you care about without even launching the app, such as the first sentence and sender of recent emails, how many text messages you received, breaking news from USA Today, weather conditions in your home area, etc. You can rearrange the Start screen and tile layout however you want, and the screen scrolls horizontally. The Start Screen works just as well on a PC or laptop with a rigid screen as it does on a touch screen or tablet, but the horizontal scrolling definitely works better on touch screens. You can use a scrollbar at the bottom to scroll with the mouse, or move your mouse cursor to screen edges to scroll, but multi-monitor users like me (I use three at home and at work) will curse at this omission.

If the Start Button is gone, how do you show the Start Screen? Using one of the following options:

• Press the Windows key on your keyboard (or the Command key if you use Windows on a Mac)
• On touch screens and tablets, swipe your finger from the top edge of the screen and flick all the way down.
• Move the mouse cursor to the bottom left of your screen. A thumbnail of the Start Screen will appear (also a pain if you use multiple monitors and you try to hit the corner on any screen other than the leftmost one).

When the Start Screen is shown, to go back to the desktop you can simply hit ESCAPE on your keyboard, or tap/click on the Desktop tile.

Windows 8 = Desktop + Start + Windows Store Apps

Windows 8 has a standard Windows desktop and will run all your Windows 7 apps. When talking about standard Windows applications in the traditional Windows 7 sense of the word, or applications designed for the Windows 8 desktop, let’s simply call them “Desktop Apps”. For the geeks out there, these are apps compiled to run on an x86 or x64 CPU architecture. So is there another type of app? Yes, these are Windows Store apps (aka Metro apps).

Microsoft introduced the Windows Store in response to the Apple App Store on iOS and Mac, and the Google Play Store. Windows Phone has had its own store called the Windows Phone Store (formerly known as the Windows Phone Marketplace) since 2010, but its Windows big brother did not, until now.

I won’t dive into the technical details of what Windows Store apps are, this is not meant to be a developer post. In a nutshell, Windows Store apps are designed to run in a special isolated environment, and the only way common folks can get them, is via the Windows Store. Desktop apps can be installed by downloading an installer from the web, via a USB stick or a DVD-ROM. Windows Store apps cannot, you have to buy them from the Windows Store (hence the name). All Windows Store apps are hosted by Microsoft, and developers must submit them through a certification process before they can be made available in the Windows Store, just like the iPhone and iPad with iOS apps.

Windows Store apps run full screen, just like the Start Screen. You can’t overlay a bunch of windows next to each other. Only desktop apps can do that. Windows Store apps can be “snapped” to the left or right, leaving the rest of the screen for another Windows Store app, allowing you to multitask, like surfing the web and reading your Twitter feed, or working on a spreadsheet in Excel while watching a Netflix movie.

What About Surface & Windows RT?

Back to Windows RT & the Surface. Microsoft Surface is a device that comes in two flavors: The Surface Pro runs Windows 8 Pro, the Surface RT runs Windows RT. I gave you this preamble about Windows 8 because I called Windows RT a flavor of Windows 8, but it really isn’t. Windows RT is a separate Windows product that shares some compatibility with Windows 8.

In essence:

Windows RT = Windows 8 - Windows Desktop

Windows RT is a Windows version that is made to run on a different hardware architecture (i.e. ARM) that is optimized for lower power devices, like tablets. Windows RT is basically a version of Windows optimized for the Microsoft Surface, and all the other rival tablet devices running on similar chips. What does this mean for you? It means the traditional Windows Desktop has been removed from Windows RT. Technically, the desktop is still there for some first-party Microsoft apps (like Office), but other application developers will not be able to run their apps on the desktop, so you might as well forget it’s there.

Windows RT only runs apps that come from the Windows Store

Only apps that have been certified by Microsoft and made available on the Windows Store can run on Windows RT. The Windows Store is shipping with the most apps of any device store at launch, and you can already find the everyday stuff you’d want: Netflix, Office, Skype, Amazon Kindle, Hulu Plus, Evernote, YouTube, eBay, Flixter, and thousands more.

The good news is that since each Windows Store application runs in a completely isolated space, it’s virtually impossible to write a virus, worm, malware or spyware for a Windows RT device. Yes, you heard me: on a Windows RT device, you no longer have to fear viruses and malware.

The other cool benefit? If you buy apps in the Windows Store, you can use those apps both on your Windows 8 PC or laptop, and your Windows RT tablet, like the Surface.

Windows RT cannot run all those apps you already have on Windows 7, Vista or XP.

You cannot install apps from a CD, DVD, USB stick or web download using Windows RT. Your traditional apps like Photoshop, QuickBooks, Office 2010, Roxio Creator, AutoCAD, Microsoft Publisher, TurboTax, etc. will NOT run on Windows RT devices. The same goes for your current PC games like World of Warcraft, Skyrim, Borderlands, Torchlight, Call of Duty, Civilization, etc. They will NOT work either on Windows RT devices, whether you bought them in a store or on Steam. The Steam client won’t work on Windows RT either.

What you will see, of course, is software vendors and game studios create specific versions of their software products and games for the Windows Store. There’s been a similar trend in the Apple App Store as we have seen more and more popular brands ship iOS versions. Microsoft Office *is* available on Windows RT, in fact it comes preinstalled on it, but you need to use the special Windows RT version. There are already 1000’s of apps in the Windows Store and that number will grow FAST since the target market includes ALL Windows RT devices (including Surface RT) and ALL Windows 8 PCs, laptops, notebooks, netbooks, ultrabooks and hybrids. The Windows family commands about 90% of the desktop market, and a significant portion of those users will migrate to Windows 8 as they buy new computers, or upgrade their current machines to Windows 8 over the next few years.

Note that some tablets run Windows 8 Pro – not Windows RT – and those tablets (like the Surface Pro), will be able to run all these classic desktop apps.

Windows RT can surf the Web and run all Web Applications

Windows RT comes with a special version of Internet Explorer 10, which means you can surf the web and access anything, even use web-based applications built with Adobe Flash. However Windows RT cannot run Rich-Internet Applications based on Silverlight (ironic, isn’t it?), so there is a chance that some rare content might not be available to you. Fret not, the whole world is standardizing on HTML5, which is supported in Windows RT and Internet Explorer 10.

Windows RT is efficient and always on

Just like iOS devices (e.g. iPhone, iPad) and Android devices, you can turn on your Windows RT tablet and use it instantly without any booting or waiting for “Sleep mode” to resume. Windows RT also consumes less power, so your tablet will run for 7-8 hours or more, unlike your laptop which probably fetches 3-6 hours.

Surface RT can be used to replace a computer. Combined with the built-in Office, you’ll be able to do a LOT. Some power users will prefer to use the full Surface Pro, and others (like me) will keep relying on a beefy laptop for their advanced work, even though they’ll also use a Windows RT tablet.

Summary: Don’t Panic

Windows 8 is an evolution. Windows RT is a revolution.

Things will be different. Change is hard. Remember the Office Ribbon debacle from a few years ago? Now we all agree it’s a much better way of working in Word or Excel. The same goes for Windows 8. People will complain at the lack of a Start button for a while. You’ll hear how there aren’t enough apps for a while. It doesn’t matter. Like any change to our habits in life, it takes about 2 weeks to get used to things (that’s how long it took me to cut sugar in my coffee 13 years ago). You’ll get used to the Start screen, and soon enough, you won’t be able to live without it. You’ll want to carry a Windows RT Surface around, and you might even want to pick-up an Xbox 360 and a Windows Phone to seamlessly connect your friends, your info, your documents, your apps, your games and your life.

If you have questions about Windows RT, Windows 8, Surface and other Windows devices, including Windows Phone, feel free to post them below in the comments section. You can also contact me on Twitter at @ActiveNick or by email at activenick@infragistics.com.

If you’re a developer interested in building apps for Surface, Windows 8 and Windows RT, Infragistics has the tools for you. You can also follow @infragistics on Twitter.

Will you upgrade to Windows 8? Are you planning on buying a Windows RT device? If so, which one?