But here g++ developers *do* provide backwards compatibility, it is called -fpermissive. And there is no "bleeding edge" at all unless you consider C++98 to be a bleeding edge standard. Anyway, old compilers still work. On my Slackware 13.1 system, I have g++-3.4 installed into /opt, and I can use it to compile a working program against system Qt4 thanks to system g++ being backwards compatible with g++-3.4 in terms of ABI.
Okay, I sit corrected. :) Yet I believe the overall general attitude among many free/libre developers remains correct. The libpng project seems like a good example. Every dot-zero release requires everybody else to scramble to fix code.
Darrell