NetSurf - Open source development, bringing HTML 4 and CSS1 standards. Documentation, screen-shots, developer information, and downloads. - http://www.netsurf-browser.org/
Webster XL - Advanced web browser from R-Comp. - http://www.arsvcs.demon.co.uk/webster/index.html
Oregano - Advanced web browser. - http://www.castle.org.uk/oregano/oregano.htm