I'm writing a Korn shell script for a client, who will use it on AIX 5.3. For testing, I'm using version 93u-1 Debian Wheezy. Is this the same version as the one I'll find on AIX?
In summary, no.
The version may differ slightly between different TL/SP levels in AIX. AIX by default uses ksh, and very little uses ksh93. Obviously, you can configure your script to use