The FD and EOS mounts are quite different. EOS lenses use electronic coupling to stop down the aperture, focus, and otherwise transmit information between the lens and the camera body. There are mechanical lenses that can be used on EOS cameras, like Tamron Adaptall lenses with the rare EOS mount, but only in full manual mode with stopped down metering. I think the new Zeiss lenses will be electronically coupled, though they are manual lenses, so I think they should have focus confirmation on EOS bodies.
Anyway, Canon made other adapters for the FD mount, for Exacta, M39 (Leica Thread Mount), and Nikon F mount. The M39 isn't hard to find, but the Exacta and Nikon adapters aren't too common.