I dowloaded the latest FOP (Fop-0.20.2RC-bin.tar.gz) and tried to run the examples in /docs/examples. The runtests.bat referred to ..\..\lib\ant.jar, which was missing. I downloaded the full Ant and copied ant.jar to the lib directory. After that the examples ran fine.
*** This bug has been marked as a duplicate of 2227 ***
batch transition to closed remaining pre-FOP1.0 resolved bugs