Abstraction languages are cool
We need more of them. I only know of a few, but the ones that I do are pretty bad ass. Seems odd that the two I use were created by the same person, but if you have used Haml and Sass then you will see the connection and some of the thinking behind them.
Language abstractions make me think differently about the way I do things. Sass taught me to be a lot tighter in my CSS, and Haml showed me how you can write out an HTML page faster than lighting. In short, because of the these, I have improved as a web developer. For that alone they get my high praise and a check mark in the cool category.