MIPS N32 firefox 3.5 beta4
It is working too. The xulrunner's ebuild is already in loongson overlay. For the mozilla-firefox ebuild, just use the one from mozilla overlay.
If you experienced segfault, try to re-emerge sqlite with no optimization. Using the bundled sqlite surely is not an optimal solution, ;)
One more thing: Xorg's siliconmotion driver is now working on yeeloong notebook: http://bugs.freedesktop.org/show_bug.cgi?id=21528