Componentizing D's garbage collector

[woh]

  If Java with all it that time and money can not create a 
performant GC, what hope has D?

  Full program tracing GC is a dead horse, it does not scale, all 
of the better Java GC's require 2x or memory of the working set 
to actually get any speed


  isolated task or allocator based memory that can use GC as a 
last resort is what you need, but D lacks in this regard