Why use Skeleton when you can use Columnal or Goldilocks?
From a brief read Foundation explicitly supports nested grids, it's handling of centering columns seems preferable, more than one type of button class, slideshow integration, etc.
I haven't seen the code but the examples for Checkbox/Radio Buttons are not accessible. If I click on the label, they do nothing.Ideally, they should toggle the checkbox/select the radio button.
I just made a WordPress port of skeleton, a quick look at foundations shows it to be very similar in terms of the responsive CSS, in fact they use exactly the same CSS, based on the 960 grid. The differences are foundations has a lot more "stuff" you can see in the github /marketing folder. It contains a slew of layout options, .php examples, javascript, fonts, etc, some are actually quite interesting and worth a look.
If it actually required PHP, or was somehow particularly useful to PHP users, or was even just identified on the website as a "PHP/CSS framework", that'd make sense. This isn't targeting a niche, it's firing a rifle blindfolded and hitting your neighbor's niche.
No, it doesn't, which is probably why nothing on the site even mentions PHP. Nonetheless, when you download Foundation it's presented PHP files that do just enough in the way of conditional server-side includes to scare away people that don't know PHP and don't want to have to unravel it out to try out a new CSS framework. That's why it's frustrating.
The page itself seems to resize pretty gracefully with one exception. Between a width of about 800-950 for me on Firefox there is a fairly sizable amount of empty space (about 750px) before the page content starts.
Very excited by this, looks very nice and pretty handy. The more choice in this space the better in my opinion. Having Tim Ferris in there makes it seem like this is going to change my life.
I like the fact that they've got boilerplate styles but their "grid" is still using floats, big strike out there.
The http://stacklayout.com/ is heaps better - using display:inline-block; for nestable grids means no more annoying column classes etc. It's a much nicer way to work
But please, tell me why I should use this rather than Skeleton (http://getskeleton.com/) or Twitter's Bootstrap (http://twitter.github.com/bootstrap/)?