@Amigadave & Djrikky:

it looks like this:
Jack on MorphOS

Well, as noticed installation script doesn't work well on MorphOS. It creates only a Jack directory in envarc and the Hollywood directory in Libs.
Manually it's possible to do some more:
the first step is to create a directory named "Jack" in the place you like on your hard disk.
Inside this directroy copy the executable of program (using the MorphOS version of course).
Copy every file inside "Distribution/Jack" directory inside your "Jack" dir and then the whole "OBjs" directory in the same place.
The Python libs should be copied inside "SYS:Libs/Python", copying the whole "Mutagen" directory and "itv.py", "jack_getmpeginfo.py", "mid3v2"and "mutagen-inspect" files.
Copy "WebP" datatype in "Sys:Classes/Datatypes".
Copy Hollywood libs in "Sys/Libs" and create a directory named "Jack" in "Sys:Prefs/Env-Archive" (this two operations could be ignored if you have just started Jack installation script, since it perform those operation by itself)
OpenURL directoy and its preference program could be ignored as MorphOS has those programs implemented yet.