Jewish Holidays  
   Dates of all major and minor Jewish holidays and fast days, with explanations, observances, and links to other articles of interest. From the OU.
   http://www.ou.org/chagim/default.htm

BAYT Hebrew Calendar  
   Monthly calendar generated as a web page, including Hebrew dates, Jewish holidays, and parsha readings. Also includes C++ source code (open source).
   http://www.bayt.org/calendar/

Hebcal Interactive Jewish Calendar  
   Interactive web interface for generating a list of Jewish dates and times customized to zip codes, converting between Hebrew and Gregorian dates.
   http://www.hebcal.com

Hebrew Calendar Science and Myths  
   A collection of resources concerning the calculation of the Hebrew calendar.
   http://www.geocities.com/Athens/1584/

Jewish/Civil Calendar Program  
   Interactive Web program that prints out Jewish and Civil calendars side-by-side. Does not list holidays in either calendar. Source code available.
   http://www.uwm.edu/~corre/calendar.html

Kaluach.net  
   Online Hebrew civil calendar portal. Also receive email reminders of holidays and personal events.
   http://www.kaluach.net

The Abib Calendar  
   The Ancient Hebrew Calendar with the original Sabbath placement according to Almighty God's instructions given to Moses for the Israelite Nation, around the year 1500 BCE, commencing at the Exodus from Egypt.
   http://www.montanaweb.com/abib/

Calendar Maven  
   Complete information about "Hebrew Calendar" software products, including "Hebrew Calendar for Windows" and "Hebrew Calendar Date Converter ActiveX Control." Evaluation copies available for download.
   http://www.calendar-maven.com

Hebrew/English Calendar with Candle Lighting Times  
   Perpetual calendar for thousands of locations world-wide.
   http://www.chabad.org/calendar/

Kaluach  
   Hebrew and english calendar for Windows. Displays a Hebrew or civil month with holidays, Shabbat portions, and halachic times. User data can be added.
   http://www.kaluach.org

Jewish Calendar on the Web  
   Converts dates between Jewish and civil calendars; displays monthly calendars and candlelighting times for different geographical location.
   http://www.hebrewcalendar.net

This Month in Jewish History  
   List of notable events in Jewish history, organized according to Gregorian calendar dates.
   http://www.wzo.org.il/en/resources/expand_subject.asp?id=144

Hebcal Jewish Calendar  
   Complete Hebrew calendar program for Unix and Windows. Candlelighting times, holidays, Omer counts, and Torah readings. C and Perl source code available, as well as a Windows executable and links to Web versions of the software.
   http://sourceforge.net/projects/hebcal

Jewish Calendar - Hebrew Calendar  
   Explains the relationship between the Hebrew civil calendar and Hebrew religious calendar and describes the history of the Hebrew month names.
   http://www.angelfire.com/pa2/passover/jewishcalendar.html