It took me quite some minutes to find out in Google how to find out the versions of ksh and dtksh in Solaris.
1. Start a shell
2. Enter vi mod
$ set -o vi
Note: The option is letter 'o' , not number zero "0".
3. Press ESC to enter command mode
4. Press Ctrl-V
Here are outputs in Solaris 8 & 9
$ Version M-11/16/88
$ Version M-12/28/93