CSS revolutionised web development, <font> and <table> were a nightmare in comparison.

But still there are times when CSS feels very limited, if you want to change a colour or margin size and have to hunt through the CSS to calculate the related changes.

But now there is

http://lesscss.org/

Which looks like it fills in some of the missing gaps - it extends the CSS syntax and to it's own format - and then generates standard CSS from this.

I'm definitely planning on using this for my next project.