What is this "dd" doc format?

Tue Dec 19 20:28:02 UTC 2017

On Tuesday, 19 December 2017 at 20:20:16 UTC, John Gabriele wrote:
> I just went looking for the source for the dlang.org overview 
> page, and found 
> [this](https://github.com/dlang/dlang.org/blob/master/overview.dd).
>
> I've seen and used a lot of markup formats, but have never run 
> across this. What format is it? Also curious: for what reasons 
> was it chosen over a more customary markup?
>
> Thanks.

ddoc, the D documentation thing https://dlang.org/spec/ddoc.html