Preprocess

Sass

See also Sass

PHP

• PHPSass - richtheeek fork of PHamlP for Drupal
• PHamlP - older

LESS

• LESS extends CSS with dynamic behavior such as variables, mixins, operations and functions. LESS runs on both the client-side (Chrome, Safari, Firefox) and server-side, with Node.js and Rhino.

PHP

• http://leafo.net/lessphp/ - June 10th 2012

Stylus

• Stylus - Expressive, robust, feature-rich CSS language built for nodejs

• nib - Stylus mixins, utilities, components, and gradient image generation

Other

• csscrush - An extensible PHP based CSS preprocessor

• PCSS - Shortcut-oriented Server-side CSS3 Preprocessor
  • Pre-defined CSS constants and PCSS functions to make the CSS writing more intuitive and to make the code slimmer and even more readable
  • Class nesting
  • Variables that can hold any kind of data
  • Default unit and default image directory to set for pre-defined functions
  • @font-face shortcut with server-side browser detection for slimmer resulting code
  • Browser-specific shortcuts are detected on server-side to avoid redundant commands (like many "-webkit", "-moz", etc.)
  • Minifies the resulting CSS file
  • PHP5