Opensource simplified calendaring solution

Question

I'm after a very simple (in my eyes) opensource calendaring solution. The basic functionality I need is:

1. provide readonly ICS feed (http/s/) (the way google cal provides it), so clients can subscribe to it
2. API to create/delete users (and their calendars) - one calendar per user is enough
3. API to manage (create, search, update, delete) events in users' calendars
4. supports events in multiple timezones

Basically I want to skip all the steps needed to create ICS myself.

For what I need Zimbra looks like an overkill.

For an answer to be considered "good", and/or accepted, it has to list each of the above features, and how/if they are supported by the proposed solution.

Answer 1

The CalDAV protocol will give you what you're looking for. The CalDAV server that I use w/ Mozilla Sunbird and my iPod Touch is DAViCal, and I like it very much. It's definitely not the only thing out there, though...

Answer 2

Here, give this a look: http://www.k5n.us/webcalendar.php