Integrating Outlook Calendar to Website / Other

Question

When the users add events to the online calendar they also can be added to the outlook calendar (synchronize). Obviously a site built using PHP can not integrate with desktop application directly, so I am looking alternative options.

Options I found:

• Using PHP ICAL library creates an .ics file and the user can download it and install. Not the most user friendly way of doing it, might work.
• Use SharePoint or exchange server- but have no previous experience working Microsoft technologies, so it not ideal.
• Use Google Calendar and Zend Library (gdata), create online calendar and add events to that. Then using Google Calendar Sync tool the user can sync the online calendar to outlook. But the problem here is the all users need a gmail account to use the Sync tool, it not ideal when you have thousands of users on the site. Unless I create one global gmail account and create many calendars on that account, if that even possible.

Questions:

1. Are there any outlook plug-ins paid or free (ideally) that can achieve this?
2. Are there any web service/ APIs that can achieve this?
3. Any other ideas or solutions?

Answer 1

Office 365 comes with an REST API that can be used to read/write to calendars. Here's some documentation on this. http://msdn.microsoft.com/office/office365/api/calendar-rest-operations

Alternatively, the EWS Managed API might be able to help you: http://msdn.microsoft.com/en-us/library/office/dd633696(v=exchg.80).aspx and http://msdn.microsoft.com/en-us/library/office/dd633702(v=exchg.80).aspx