Jewish Calendar - Interface for finding dates in the Hebrew calendar, with holidays and memorial days. Uses PHP calendar software. - http://mike-r.com/%7erechtman/jh.html
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/holidays
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
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
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
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
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
Kaluach.net - Online Hebrew civil calendar portal. Also receive email reminders of holidays and personal events. - http://www.kaluach.net
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
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