Gcal can be used for a lot of calendar related questions. A zillion calendar options. Of course, if you are not a calendar freak, this is not the main selling point.

When I hear "mail merge," I usually think of personalizing letters and printing envelopes. However, many other projects can make use of mail merge. This year I tackled a new Christmas gift project by using mail merge in OpenOffice.org (OOo) to create a tear-off daily calendar, personalized with holidays and family events. Here's how.

There was a time when I had a work calendar on my employer's Exchange server and a home calendar in Kontact. Then my wife had a paper calendar on the wall in our office. Addresses and phone numbers were spread across Exchange at work, Kontact and Quicken at home, and a vast array of sticky notes and scratch pieces of paper generously scattered throughout the house.

"As I’ve mentioned before, the Mozilla Calendar project, which includes the Lightning calendar extension to Thunderbird, is moving right along. It’s currently at version 0.7, heading towards a 0.8 release ASAP. I’ve asked the Calendar team how I can help, and the answer has been clear — they need more developers..."

Let's take a look at three projects that are aimed at showing calendar information through a Web interface: WebCalendar, VCalendar, and CaLogic. These projects run on a LAMP server and provide a Web interface to calendar events.

"I’ve found a cool Howto about syncing your Icedove/Thunderbird Lightning calendar with Google Calendar, Zimbra, or any other iCal server (see Wikipedia for a list of servers which support it)..."

KonsoleKalendar lets you interact with the calendar application in KDE's Kontact from the command-line. Aside from possibly using this handy utility via SSH to remotely add an event to your calendar, you could probably also use it in a Bash, Python, or other script.

To integrate google calendar events into your gnome desktop, go to google calendar,

Sunbird, Mozilla's calendar application, supports extensions just as Firefox and Thunderbird do. What kind of extensions work with a calendar? How about being able to get a weather forecast when you're setting up a golf date, or exporting your desktop calendar to a Web service?