Do you really belive this web 2.0 thing is about creating web-based clones of desktop applications? I have seen thousands of web applications with calendar support that all try to implement a calendar interface. But only few succeed. One example is Google Calendar which is quite well-made, but does not yet reach the ease of use of a desktop calendar application like Outlook, iCal or Evolution.
Why are web-based calendars nonetheless popular? The most important reason is that they allow exchange and sharing of data is a very easy and transparent way. No special client software needs to be installed and any user can publish and subscribe events.
This approach of building your own calendar interface in order to foster sharing will soon come to an end because in the future every user will have an desktop calendar interface that allows publishing and subscription of events. The feature to be able to subscribe to your friend's or colleague's events or important events of sports teams, public holidays has been made available to a wider audience by Apple with their iCal product which allows subscribing to calendars via HTTP and publishing via WebDAV, which is, essentially HTTP, too.
Recent versions of Novell's Evolution support the subscription feature as well and being able to publish and subscribe to calendars is one killer feature of Google Calendar. The latest and most important step in this series of development is the upcoming support for calendar subscriptions in Microsoft Outlook 2007
. With this new version every computer user will be able to use one of the desktop calendar products like
or
Google Calendar
. There are other web-based calendar applications as well, but they will have a hard time to compete in terms of usability no matter how much AJAX-juice they use.
What is the consequence for creators of date-sensitive applications? The consequence is that you do not have to build a calendar interface on your own. All you need is to provide a date entry field with an appropriate widget and a subscription link for the calendar. Your users will be able to view all events, those resulting from your application and all other events that are of importance to the user in their favorite calendar application. This will be a tailor-made calendar application that your own calendar interface will hardly match in terms of usability, desktop integration and familiarity.