[yjftsjthsd-h]

If bootstrapping/portability is the goal, probably C.

[damnstraight]

Conveniently there are already C++ compilers bootstrappable with C.

[tavert]

Any that are both open-source and C++11 compliant? Guess you can still build g++-4.6 with just C, then a newer g++ from that, but it's a bit of a pain.