Web Calendar Servers
Calcium and iCal are both web calendar products. Once the
software is installed on a single host computer, any number of
users can point their web browsers to the system to view, edit,
and manage the calendars.
Calcium has more features than iCal, and can be installed on
almost any server. iCal is Windows-only - of course, users can
access it from any kind of computer - and has its own built-in
- Perl CGI program (comes with Perl source code)
- Runs under control of an existing web server
(e.g., Apache, IIS and others)
- Runs on any machine, including remotely hosted sites
- Microsoft Windows executable program
- Has a built-in web server
- Runs on all Microsoft Windows platforms
(but no other operating systems)
Calcium and iCal are both rich in features. Both can merge data
from multiple calendars, synchronize data with Outlook and Palm
devices, provide a variety of calendar views, send email
notifications and reminders, as well as support user defineable
custom fields, different languages, iCalendar data exchange, RSS
feeds and all of the other commonly expected features.
However, Calcium has more features than iCal; and in
many cases where the two products have the same feature, Calcium
will provide more options and flexibility. Calcium has been
designed for the highest requirements, with features such as
support for per-user security, time zones, secure socket
connections, and LDAP authentication.
These are features and options provided by Calcium, but not
- User Security Accounts: Calcium has user login
accounts that provide a number of features throughout
the system. A login account can be assigned specific
access rights to individual calendars. For example, a
user can have Administration rights for some calendars,
edit rights to some others, and view-only rights to
others. User accounts also allow for:
- accurate auditing, such as who made changes to a
calendar and when they were made
- letting users post events to a common calendar,
but allowing only the user who created an event to
- user management using User Groups; e.g. an
administrative group could be given edit rights to a
newly created calendar. Then, every user in that
group would have these rights.
- Secure Socket Connections: If your web server
provides HTTPS, access to Calcium calendars will also be
secure, since Calcium runs under control of the web
server. (iCal's built-in server does not support HTTPS.)
- Time Zone Support: Different users can view the
same calendar using different time zones. For example,
if a person in New York adds an event scheduled for 1pm,
a user viewing that calendar from San Francisco would
see the time for the same event displayed as 10am. Each
user can have their own time zone offset setting.
- LDAP / Active Directory support: You can choose
to authenticate users against your existing LDAP
directory; you still have the option to create and use
Calcium's built-in user logins at the same time.
- Multiple categories per event: Both iCal and
Calcium allow specifying a category for an
event. However, Calcium allows an event to have any
number of categories assigned, while iCal supports just
one. This provides for more sophisticated filter views
of a calendar, as well as more flexibility when
including events from other calendars by category.
- More recurring event options: Calcium has
additional options for repeating events, such as
repeating every 5th, 6th, 7th, ... week, repeat on the
5th week of the month if it exists, repeat ever other
month, every 2nd month .... every 6th month.
- Defined Time Periods: Time periods allow you to
assign names to time ranges. E.g. 8:00 am to 9:15 am
could be defined as Class Period One. When an
event as added to the calendar this name could be
selected rather than specific time assignments.
- Time Increments: in Calcium, event times can be
assigned down to the minute. The minimum time increment
in iCal is 5 minutes.
- Event Sorting: iCal can display events in a
day sorted alphabetically by text or by time. Calcium has
options to sort alphabetically, time, category or by included
calendar. Calcium also provides secondary sorting.
- Additional Calendar Views: Calcium provides
Quarterly and Fiscal data views.
- And More: There are many other extras in
Calcium, included email aliases, more font and color
assignments, better CSS control, more RSS options,