Recs.
Updated
Pleeease is a Node.js application that easily process your CSS. It simplifies the use of preprocessors and combines them with best postprocessors. It helps create clean stylesheets, support older browsers and offers better maintenability. This means no more Compass for prefixes, no more rem mixins, and so on. Everything is getting simpler now and almost magic*.
Specs
Pros
Pro All-in-one post processor
preprocess CSS (experimental)
adds prefixes, based on Autoprefixer
provides fallbacks for rem unit, CSS3 pseudo-elements notation
adds opacity filter for IE8
converts CSS shorthand filters to SVG equivalent
packs same media-query in one @media rule
inlines @import styles
minifies the result
generates sourcemaps from pre- to postprocessors
Pro Rem fallback
Rem unites are not supported in IE8 and below, so Pleeease provides a pixel fallback.
Pro Uses Autoprefixer
Pleeease uses Autoprefixer to add vendor prefixes based on which browsers you want to support (prefixes are added based on information from caniuse.com.