Peter Weilbacher has released (11/8/2006) unofficial builds of Seamonkey 1.0.6 and 1.1 beta, Firefox 1.5.0.8, and Thunderbird 1.5.0.8 that add MNG/JNG support, SVG and Canvas support, Rich Walsh's WPS enhancements, EA URL tagging of downloads, and more. There are also enhanced builds of Firefox 2.0, and Thunderbird 2.0 beta.
http://weilbacher.org/Mozilla/builds.html
Source: OS/2 Warp News and Rumors