Ha the Songplayer which is only an 'example' of what MUI Royale can do is currently the best audio player available for AmigaOS!!! (aside from the most recent version of AmigaAmp that has only just got the M4A treatment)
With a little bit of work this alone would be a great little app to have!
Having said that... I find it deeply flawed the way Hollywood handles AHI, whether this is a fault in Hollywood itself or AHI I do not know.. take the following example:
I have Jack running all the time, if I go into Configuration and select an audio Chime it works. If then compile/run Songplayer, select a song, it plays. If I then close Songplayer and go back to Jack and replay an audio Chime it no longer works until I restart Jack.
@djrikki: Normally, the XML tags are identical to the class name, e.g. <gauge>, <button>, <listview>, <cycle> etc. There are some exceptions, though. These are mentioned in the overview chapter for each class then.
Concerning the AHI problem: It's a limitation of AHI. It is not able to handle more than one application using its library interface. On MorphOS there is a specific driver which works around this issue. I might drop the library interface in the future and go with the device interface which doesn't have this limitation but this would be quite a lot of work and it would also make some things slower or even unavailable.