Interoperability, a case study: google calendar; iCalendar, hCalendar, CalDAV; How to remotely synchronize Google Calendar events to/from your Windows Mobile device (using its local internet connection) or your Iphone.ipad, your desktop computer?; google calendar better than Microsoft Outlook, Apple iCal, Mozilla Sunbird?

1) Interoperability of google calendar 
Automatic synchronization between Google calendars (Google web calendar, Google Android calendar) and Microsoft calendars (outlook; windows mobile) and Mac calendars (desktop, iphone, ipad...), and other calendars (mozilla sunbird, yahoo calendars...).

The interoperability of google calendar is very good. I found one problem: for windows mobile, it is not easy (se below). Use GMobileSync for this case. All visible calendars on Google Calendar will be synchronized to local. Local newly added appointments will only be added to the "default" calendars on Google Calendar. 

GMobileSync is an open-source project (codeplex.com).
Download the .cab:
http://gmobilesync.codeplex.com/releases/view/23265

2) 7 reasons to use Google Calendar
a) Sync with your desktop applications and mobile phone's app
Access your calendar however and whenever you want by syncing events with Microsoft Outlook, Apple iCal and Mozilla Sunbird.
With two-way syncing to your mobile phone’s built-in calendar or a mobile version of Google Calendar that’s made for the small screen, you can access your calendar while you’re away from your desk.
You can sync Google Calendar with mobile devices like iPhone and Android and calendar applications like Microsoft Outlook and Apple iCal.
Learn about syncing options at :
http://www.google.com/support/bin/answer.py?answer=1086559
http://www.google.com/support/calendar/bin/answer.py?hl=en&answer=98563&ctx=cb&src=cb&cbid=37xdqsou4j6r

b) Work offline (with chrome)
Know where you’re supposed to be even when you don’t have internet access. With offline access, you can view a read-only version of your calendar no matter where you are.

c) Share/send invitations: Let your co-workers, family, and friends see your calendar, and view schedules that others have shared with you. When you know when everyone is free or busy, scheduling is a snap. Invite other people to events on your calendar. Guests can RSVP to your events by email or via Google Calendar.

d) many Keyboard shortcuts: http://www.google.com/support/calendar/bin/answer.py?answer=37034&hlrm=fr

e) Using the search function in Google Calendar is similar to searching on Google.com.

f) many labs features: http://www.google.com/support/calendar/bin/answer.py?hl=en&answer=154174&ctx=cb&src=cb&cbid=-c3c3nqhytumw

g) convergence: many links with the google services (Gmail, igoogle, blogger, etc)...

http://www.google.com/support/calendar/
http://www.google.com/intl/en/googlecalendar/about.html

-----------There are 2 ways to access Google Calendar on Android devices:

• Calendar app
• Browser

For the best experience with Google Calendar on Android, use the preinstalled Calendar application.
The Calendar app on Android comes with the following features:

1. No setup required. Your Google Calendar is ready to go after you initially sign into the phone.
2. Sync. Changes on your computer will appear on your device and vice versa.
3. Integrated reminders. Get notified on your device's status bar whenever an event reminder occurs.
4. Google Calendar basics. Support for creating, editing, and deleting events, plus multiple calendars.

If you don't want to pay for MB transferred by edge,/3G and if you just want to only synchronize with wifi (free hot spot...), 3 settings must be controlled:

1. Accounts & sync: select a)Background data, b)Auto-sync and c)xxxx@gmail.com (sync ON) and select Sync Calendar, (after the sync., disabling background data extends battery life and lowers data use).
2. Wireless & networks: a) select Wi-Fi; b) Mobile network settings (take care of "Data enabled" and "data roaming" and Network Mode (before sync. select GSM; after sync. select "GSM/WCDMA auto").
3. Open your android calendar, select "more", select "My calendar" synced,visible AND xxxx@gmail.com  synced,visible (and other web calendar, Contacts' bithday, Weather, Sunrise and sunset...)

----------Mac users can sync Google Calendar with Apple iCal and Mozilla Sunbird.
http://www.google.com/support/bin/answer.py?answer=1086553#1086557

Google Calendar syncs with both Apple iCal and Mozilla Sunbird via CalDAV, an open protocol that allows calendar access via WebDAV.

You'll be able to view and edit your Google Calendar events directly in Apple iCal and Mozilla Sunbird. Any changes you make in Apple iCal or Mozilla Sunbird will automatically appear in Google Calendar the next time you sign in (and vice versa). If you use Apple iCal or Mozilla Sunbird while offline, changes you make will be saved and updated in Google Calendar when you get back online.
Sync is only supported for Apple iCal 3.x and up (on Mac OS X v10.5+)

There are 2 supported methods of syncing Google Calendar with iPhone or iPad: Google Sync and the CalDAV protocol.


-----------windows users can sync Google Calendar with Microsoft Outlook and Mozilla Sunbird.

Google Calendar syncs with Microsoft Outlook Calendar via the Google Calendar Sync application.
Google Calendar Sync is only compatible with Microsoft Outlook versions 2003, 2007, 2010 (32-bit) and operating systems Windows XP, Windows Vista, and Windows 7.



-----------windows mobile phone users can sync Google Calendar 
1)you must use Microsoft Exchange ActiveSync application:
http://www.google.com/support/mobile/bin/answer.py?answer=138636
2)or you can use GMobileSync (an open-source project (codeplex.com)).
http://gmobilesync.codeplex.com/releases/view/23265

-----------many Google products for mobile devices:
http://www.google.com/support/mobile/

for Google Calendar :
http://www.google.com/support/mobile/bin/answer.py?hl=en&answer=174827

Google Calendar is a web-based calendar, so if your phone has a web browser on it, all you have to do is go to m.google.com/calendar (on your phone). You'll get a mobile version of Google Calendar that's optimized for your device.

-----------Google Calendar ad BlackBerry devices:

With your BlackBerry device, you will be able to access Google Calendar in two different ways:
- Browser
- Sync

Browser
- Google Calendar for mobile browsers
Just like you would on a computer, simply go to http://www.google.com/calendar in your BlackBerry's web browser to access Google Calendar. There's no setup required. The mobile browser interface of Google Calendar is always in sync with the main Google Calendar server.

Sync
- Google Sync
If you prefer to use your BlackBerry's native Calendar application, you can integrate Google Calendar with your device using Google Sync. You'll get wireless synchronization of Google Calendar to the built-in Calendar program on your device.

@@@@@@@@@CalDAV
CalDAV (Calendaring Extensions to WebDAV) is an Internet standard allowing a client to access scheduling information on a remote server.
http://en.wikipedia.org/wiki/CalDAV
http://fr.wikipedia.org/wiki/CalDAV

@@@@@@@@ICalendar
http://en.wikipedia.org/wiki/ICalendar
iCalendar is a computer file format. It is designed to be independent of the transport protocol.
iCalendar is supported by a large number of products:

• Google Calendar, 
• Apple iCal,
• Yahoo! Calendar,
• IBM Lotus Notes,
• Lightning extension for Mozilla Thunderbird and SeaMonkey, 
• and partially by Microsoft Outlook. 

@@@@@@@@hCalendar
We can embed iCalendar data in web pages using hCalendar (short for HTML iCalendar), a 1:1 microformat representation of iCalendar in semantic (X)HTML.
Facebook, wikipedia, google use hCalendar.

hCalendar allows parsing tools (see browser add-ons like Firefox's Operator extension http://en.wikipedia.org/wiki/Operator_(extension)) to extract/display the details of the event,  or search them, or to load them into a calendar program, for instance.