ZX is a bunch CSS classes to help authors and developers create flexible and consistent cross-browser layouts. And make applying Media Queries easier. That’s the plan anyway.
The ZX CSS Layout example page ain’t pretty but hopefully there’s enough information to understand what’s going on and to try it out.
There are quite a few of these layout helping CSS frameworky type things around, a couple I’ve listed, and they’re definitely worth trying out to see which shoe fits the bill oddie, or something like that.