This spec allows you to define your own selector as an alias for a list of other selectors …
CSS Vendor prefixes considered important
Lately, there has been a lot of hate towards vendor prefixes. First, PPK wrote about them, and then a some other people did. The proposed solution to the ‘problem’ of vendor prefixes is to get rid of them in favor of one
-beta- prefix. Simply put: That won’t work.
Why they exist
You see, vendor prefixes exist for one important reason. Vendor prefixes are used for unfinished specifications. Unfinished specifications change. They evolve. Sometimes they don’t describe the implementation at all, or the syntax has yet to be agreed upon. They are not done yet. They are unfinished.
This means browsers could, and will implement things differently. To give a concrete example: Gecko and Webkit implemented the
border-radius syntax differently. Had there been only one “
-beta-” prefix, you could not have used border-radius in a cross browser way. That doesn’t seem like a real solution, does it?
“But I have to type so much!”
Sure, typing -moz-, -webkit, -o- again and again gets annoying, but come on, you’re a developer. It’s trivial to make a snippet (or whatever your editor calls them) for this, or to use a Sass or LESS mixin. Tools will save us.
Vendor prefixes are awesome
Vendor prefixes allow us to test out new technologies, they allow different browsers to implement them in the way they seem most conforming to the specification (at that moment). This in turn allows developers to deal with browser differences by setting different values for each vendor prefix.
Browsers get to test out different implementations, and developers get early access to new possibilities. That seems like an excellent deal to me.
Internet explorer has quite some odd ways to render my CSS. Luckily, the IE Team developed a way to hide certain parts of your HTML for other browsers: Conditional Comments. The only caveat here is that they only work in the HTML. When you use this as it’s commonly used, to link to a special…
The :not() selector is only supported by modern browsers, :not(IE). …