[Animats]

That's what gets me. The div/float/clear approach, which is one-dimensional, is a poor match to "modern grid layouts". Elaborate CSS gimmicks are needed to fake it. Here are four of them: http://www.sitepoint.com/easy-responsive-css-grid-layouts/ One just uses tables.

Now we have "grid" as a primitive in CSS. Inevitably, it needs a special case for some versions of Internet Explorer. There's "grid", and there's "-ms-grid". Here's the W3C spec.

http://dev.w3.org/csswg/css-grid/

It's a lot like tables, but it uses different terminology and has some extra bells and whistles, so that makes it OK.