plan is a calendar and day planner program for the X Window System based on the Motif widget set. plan is free software released under a custom permissive license. Its main window shows a month (the current one by default); the user can insert appointments at given days and time. An accompanying program pland reminds the user of appointments by showing a warning window or running an arbitrary shell script. Other features of plan are: * configurability of warnings * week/month/year views * periodic appointments * appointment types * client/server multiuser mode