Note for compiling the phpdocumentor help using the (current) revision 810 of
build.xml:

Use phing 2.2.0 tu build it. Version phing 2.3.0beta1 will not work.

UPDATE: If you edit the build.xml file and change the taskname from phpdoc to
phpdocext it will work with phing 2.3.0beta1.

If you used pear to install phing, then make sure, that the pear subfolder
pear/data is also in your php include_path. Otherwise you will get an error
'BUILD FAILED Can't load default task list'.

Note that there is a bug in phing 2.2.0 under windows. To fix it replace
in bin\phing.bat the line
set PHP_CLASSPATH="%PHING_HOME%\classes"
by
set PHP_CLASSPATH=%PHING_HOME%\classes

If you use phing 2.2.0 and fixed the bug calling tools\build>phing generate-docs
should compile the the help to build/tobuild/docs/API/phpdoc/html