Looking for a good calendar

I am just curious if anyone has experience with a good calendar. I have read about a couple different ones, but I haven’t found as much info as I would like. Plus, I would like to hear actual user opinions, as compared to author comments. Thanks in advance.

I’ve been using a customized version of Active Calendar since it’s XHTML, CSS, PHP and optionally MySQL based ( http://www.micronetwork.de/activecalendar/ ). I’ve got it on 3 of my MODx sites and it’s working great. I haven’t mustered up the time/energy yet to document how I did it but it’s on my to-do list.