Microsoft has officially detailed its three versions of Windows 8, set to launch later this year, including Windows 8, Windows 8 Pro and Windows RT, formerly known as Windows on ARM. As the "Pro" name might suggest, Windows 8 Pro is targeted at "tech enthusiasts and business/technical professionals" while the regular Windows 8 is the version Microsoft believes more suited to the mass market. However, Windows RT will be specifically for ARM-based tablets and PCs, and come preloaded with touch-optimized desktop versions of the new Word, Excel, PowerPoint and OneNote.
"For new apps, the focus for Windows RT is development on the new Windows runtime, or WinRT," Microsoft says, "which we unveiled in September and forms the foundation of a new generation of cloud-enabled, touch-enabled, web-connected apps of all kinds." It will also support device encryption, though not x86 desktop software, Storage Spaces or Windows Media Player.
Windows 8 Pro, meanwhile, will add support for more complex encryption, virtualization, PC management and domain connectivity to Windows 8, though Media Center functionality will be a paid "media pack" add-on.
Microsoft is also readying a small number of local-language specific versions of Windows 8, which will be offered in China and "a small set of select emerging markets."
Windows RT will only be sold on new computers, whereas Windows 8 and Windows 8 Pro will be offered as upgrades for current Windows 7 users. Pricing for those upgrades is yet to be confirmed, though Microsoft promises it will be revealed in the coming months.
Below, the comparison chart of the three versions; click for full-sized (opens in new window):