First I assume you have used abaco - it is incomplete but its the best plan9 has at present - without using linuxemu.
There is cfront c++ but this is so old it would probably not be worth getting it to work - templates never worked in AT&T cfront. The exception to this the HP cfront implementation which they might release if hassled. If you are saying that you are willing to take this on (getting a modern native plan9 web browser running) I may be able to help in some areas (NDAs annotingly prevent me discussing it here). One idea I was considering for several years was trying to get Dillo running as a fairly compliant browser, initially under an X11 server but later you might be able to merge the framebuffer backend to dillo (via a library I cannot remember) and replace it with a library which talks /dev/draw rather than linux framebuffer. just some random thoughts. -Steve