Xcal is an interactive calendar program with alarms and a notebook.

Pscal is an program that generates calendars in PostScript.

Xcal_cal is a program that takes you calendar entries and makes a file
for the standard UNIX calendar program to send you mail.

Xcalev is a program that is used to pre-load your calendar with all
those birthdays that you are prone to forget.

Xcalpr is a program that prints calendar files out to a terminal. Nice
if you have no X screen. This also can be used to generate a file for
the UNIX calendar program.