mobile IE6
No, it´s not based on mobile IE6 nor Desktop IE6, as matter of fact, Tasman is a way better than IE6(mobile or desktop) in terms of standards compliance, tasman is based on old IE mac version.
more info:
http://en.wikipedia.org/wiki/Tasman_(layout_engine)My provider(Portugal Telecom) has some xhtml pages on a server and i redirect them on my router to my own web server, so i can display content on a normal unmodified box, actualy i have written a youtube client(using youtube api and some magic to get the actual flv url from youtube IDs) in php+xhtml+css+javascript using a custom CGI written in C that wrapps FFmpeg, so i can do the transcoding of flash video(FLV) to WMV9 on the fly. It´s currently in beta, but i plan to release it (GPL) when it´s ready.
I normally use Firefox and Microsoft Entourage for Mac 2004 (2008 doesn´t use Tasman, it uses Apple's WebKit) for testing since we don´t have access to the official emulator.