Is the HDK available on the Mac OS X version of Apprentice HD? I cannot find the hdkinstall command anywhere.

hdkinstall was removed in H9.5. The headers should be in
$HFS/toolkit/include. As for actually compiling, one person seems to have done it … http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=13031&highlight=hdk+osx [sidefx.com]

Go to /Library/Frameworks/Houdini.framework/Resources/ and look around.

The headers / samples are in the toolkit directory

Make sure to set up your environment (source houdini_setup) and you should have no problem building anything