D as System Language

[Columbus via Digitalmars-d]

On Monday, 30 March 2015 at 15:39:07 UTC, Adam D. Ruppe wrote:
> Basically you can start with an empty runtime and then add back 
> missing functions as needed to get it to compile.

What do you mean by "an empty runtime"?
What does a runtime need?

On Monday, 30 March 2015 at 15:42:46 UTC, weaselcat wrote:
> https://github.com/xomboverlord/xomb

Yes I know, but it is D1 and not D2.
I do not exactly understand the differences, but I want to use D2
because I don't know what would be better when I'd use D1.