I've been looking online for some Postprocessors for dealing with Vendor Prefixes and these are the libraries I came across.
Autoprefixer
Prefixr, which will do it for you.
Prefix-free, which will also do it for you but client-side.
However what differentiates one of these postprocessors from the others and visa versa?
Well, autoprefixer is meant to be integrated into your asset pipeline. So, for example, if you are using Sass or LESS, you can attach autoprefixer to it. Then it's automatic. While using it, I never even have to think about prefixes.
If you're editing the final css file directly, autoprefixer may seem like more of a hassle, I suppose. But in that case, you might want to check out the benefits of Sass/LESS.
Prefix-free runs on the client side - so that will be easier for a static css file, but it may impact page load time (although, the css download itself may be smaller.)
I think Prefixr is a UI? I'm not as familiar, but in that case it's an app that does it for you. The others are "set it and forget it" solutions to the problem.