sass vs less vs stylus vs CSS

SASS 1$siteWidth: 1024px;2$gutterWidth: 20px;3$sidebarWidth: 300px;45body {6margin: 0 auto;7width: $siteWidth;8}9.content {10float: left;11width: $siteWidth - ($sidebarWidth+$gutterWidth);12}13.sidebar {14float: left;15margin-left: $gutterWidth;16wid...