YUI CSS库
http://developer.yahoo.com/yui/

YAML（Yet Another Multicolumn Layout）
http://www.yaml.de/en/

Content with Style: A CSS Framework
http://www.contentwithstyle.co.uk/Articles/17/

Blueprint
http://code.google.com/p/blueprintcss/

tripoli
http://monc.se/tripoli/

Elements
http://elements.projectdesigns.org/index.html

WYMstyle: a CSS framework
http://www.wymstyle.org/en/

taffy-css-framework
http://code.google.com/p/taffy-css-framework/