not very important but it's "object pascal" not "objective c".
Anyway, saying Delphi is enough, and the tool used to develop is very old: Turbo Delphi. It is officially dismissed, but you can
search the web for more luck.
For the libraries refer to the file "developer notes.txt" you find in the archive of HFS sources.
It can be a real mess, so first consider that some features can be achieved through scripting.