I have handed maintenance of pdksh over to Michael Rendell <michael@cs.mun.ca> who is producing the v5 release (for UNIX anyway) which is a major improvement over 4.9 and provides autoconfig support.
The latest pdksh-5 version should be available from
ftp://ftp.cs.mun.ca/pub/pdksh/pdksh-5.*.tar.gz
The * means the name varies based on the version.