Where aren't people using any Quake mapping tools?

I thought the point of BSP Factory was that it converted the HalfLife maps that Blitz can't load. And HalfLife BSP's can indeed be compiled without the use of ID's compiler. I think Quark and the Zoner Half Life Tools are a legally sound editor and compiler combination.

This is all regurgitated from what I've read previously, though, so don't take it as fact until you've verified.