Newest build of Windows 8.
August 1st, 2013
http://windows.microsoft.com/en-US/windows-8/preview
It’s only in alpha stage, so you can get the latest free from Microsoft.
The developer preview is old. The consumer preview will be a lot better and it’s release is only a couple of weeks away.
Windows 8 Developer Preview Build 8102 M3
32-bit (x86)
http://www.softpedia.com/dyn-postdownload.php?p=196339&t=0&i=1
64-bit (x64)
http://www.softpedia.com/dyn-postdownload.php?p=196339&t=0&i=2
64-bit (x64) With Developer Tools
http://www.softpedia.com/dyn-postdownload.php?p=196339&t=0&i=3