Knox is a new feature that is part of Samsung's SAFE program (which stands for Samsung For Enterprises). It lets you divide your phone into two halves, one side for work and one side for your personal life.
The work side can be controlled by an employer's IT department. IT can dictate the apps and add all the pesky security features and controls they want. The personal side is controlled by you, and that's where you can load whatever games or other Android apps you want.
Knox is available on any SAFE-certified phone. Right now that's the Samsung Galaxy S III and Galaxy Note II.
So far, reviewers like it. The Verge's Chris Ziegler say it's easy to tell the work side from personal side and switching between them is quick. CNET's walkthough showed it was simple to use, too.
Samsung isn't the first to come up with this idea.
VMware hoped to bring Horizon to the iPhone, too. That would have been big news, because it would have meant Apple was willing to let VMware fiddle with iOS. Not so. VMware does have an iOS app called Horizon
Knox and SAFE are two of Samsung's biggest weapons to win against Apple. Samsung is deliberately loading its smartphones with features to make enterprise IT departments love it. Its hope is that this will encourage IT departments to buy fleets of phones for their employees. Or, if they don't buy the phones, Samsung would like IT professionals to ask their employees to buy Samsung SAFE devices.
Stay tuned for BI Intelligence's in-depth analysis of how Samsung is pursing the enterprise, publishing soon.