Okay, that meshes with what I remembered along the years - that the idea was for a common code base, but things... fractured along the way, and a number of side-projects that were Windows branded had to be brought back into the fold, with varying degrees of success. As I understand it, the APIs are quite unified now, but the implementation code is still all over the map in some cases. I could be wrong, not having any sources deep in the colon of Redmond. :)

Absolutely agree on that last point, however.