libcurses.so.5  --  What is it and where can I get it?

I have downloaded several packages on my computer that won't execute, and
they complain that they can't find "libcurses.so.5".   Does anybody know
what this is and where it can be found?

One of the applications that I'm really wanting to play with, is something
called vms-empire.   Unfortunately, this game is one of several that is
wanting libcurses.so.5.

Thanks for any help and/or guidance.

Regards,