[mpu]

It's much much smaller (I think libfirm is over 100kloc, QBE is about 6k).

But the major difference is the IL: I use a human-readable and easily-printable text IL. This means that you don't need a graph-viewing tool to read the IL (it's just text) and that you can modify the IL between two passes super easily. This simple IL is a blessing when debugging a compiler.

I think QBE also has better support for the x64 ABI.

Finally, it is much less advanced (less optimizations, less tested) than libfirm and supports only x64 as a target.

This is a sketchy comparison.

[swah]

Its probably also easy for you to output a symbol-file to be used by IDE/editors, right?