I don't know about ksh93, but I looked in to the MirBSD Korn Shell (mksh) a while ago as a replacement for tcsh (before eventually settling on zsh). I actually still use it on my server (as that's an old machine and mksh uses a lot less memory).
You may want to look in to it, as it's probably better maintained than ksh93, and I found the manpage to be excellent.
Here's my config file, by the way:
https://github.com/Carpetsmoker/dotf...ld/mksh/mkshrc