setld is specific to Tru64. See
UNIXguide.net for information on the differences of commands in various flavors of UNIX.
As far as getting the version, one way is to use the strings command -
# strings your-package |grep -i version
Not all packages put the version inside the executable, but this might help with some.
Also check out the info at
tru64.org - search for " How do I figure out what version of Digital UNIX I have". It shows using the strings command searching for Rev.