For Law Enforcement outside of the US, some of them have to carry chamber empty.  I saw this posted online. It was posted by a Filipino Gun Club. The holster allows the user to chamber a round as they draw the gun out.

It reminds me of the the Crye Gun Clip in that drawing the weapon out is a tilting/rocking out motion rather than a standard upward draw. However one issue I have is that the trigger is not covered up. It looks like there is some sort of trigger block when the Glock is locked in the holster. But that is not as good as a proper holster that completely covers the holster.