Calendar Magic
A program that compares 23 different calendar systems and other calendar related tools.
http://www.stokepoges.plus.com/calendar.htm

A Better Calendar
A better calendar is as simple as ABC
http://www.bettercalendar.com/

HotShift Calendar
Download site for a freeware/shareware calendar program for firefighters and other workers on a rotating platoon type schedule. Features include desktop calendar, printing and web calendar generator.
http://hotshift.tripod.com/

CDAY Calendar Almanac
Displays historical anniversaries (birthdays, events) and date in multiple calendar systems, including Gregorian, Hebrew, Mayan, Julian, JDN, and Shire (Lord of the Rings), and Great Underground Empire (Zork).
http://cday.sourceforge.net/

Calgoo Calendar
Share your Outlook, iCal, and Google Calendars. Gives you iCal calendar sync & Outlook calendar sync. Free calendar download, view your Google Calendar offline.
http://www.calgoo.com

Calendar Studies
Articles on the Gregorian and Julian calendars, the ISO date format, the Julian day number system, the Maya calendar, the Goddess lunar calendar, the Liberalia Triday Calendar and others.
http://www.hermetic.ch/cal_stud.htm

ColdFusion Calendar Applications
ColdFusion unencrypted applications including evCal Events Calendar, MyCal Personal Events Calendar, Red Reservations Calendar, TimeSheet Review are available at a very low cost.
http://www.dazzlindonna.com/blog/coldfusion-calendar-scripts-and-coldfusion-applications/

Calendar
Panel ActiveX control
http://icxr.com/accldr.html

Maya Calendar
A thorough explanation of the Maya Calendar, covering the long count, the tzolkin-haab and the relation between the Maya Calendar and the European.
http://www.hermetic.ch/cal_stud/maya/cont.htm

PHP Availability Calendar
This is PHP Availability calendar script that shows availability of your rental based on calendar data.
http://www.merenkov.com/calendar/