Does HP-UX On Itanium always come with PA-RISC compatibility

Does anybody know if HP-UX on Itanium always comes with backwards compatibility for PA-RISC applications?

I've heard that there is an emulator called Aries which should do the trick, I just need to know if it always comes as standard with HP-UX Itanium systems.

Any help would be greatly appreciated.

Got these?

/usr/lib/hpux32/aries32.so 
/usr/lib/hpux32/pa_boot32.so 
/usr/lib/hpux64/aries64.so 
/usr/lib/hpux64/pa_boot64.so 

..then you have aries. AFAIK it comes with HPUX 11i 1.5

Hi,

By default HPUX supports backward compatibility. Aries is used to simulate PA-RISC environment for PA-RISC Application.

But, I always suggest to recompile your application on Itanium systems to get all the benefit of IA platform.

Regards,
Venky

If you want to read a bit more on the subject:
Aries Binary Translator