So what about -betterC flag?

[Rel via Digitalmars-d]

I remember that there was some buzz around undocumented -betterC 
compiler flag that should allow people get away from hard 
druntime dependencies and write bare metal code, drivers or 
kernel modules in some limited D subset. Could you make some 
comments about it. Does it exists and is it practical thing to 
do? What limitations does it require for your code? Is anyone 
using it right now and in what context? Thanks!