iCal

iCal is Apple’s built-in calendaring application. You either love its simplicity or hate its limitations.

defaults write com.apple.iCal 'Default duration in minutes for new event' 30

defaults write com.apple.iCal IncludeDebugMenu 1

This allows you to, among other things, change the number of days displayed in the week view.

• Using the mouse scroll wheel with Alt/Option held down changes the visible time scale.

• BusySync
• RemoteCalendars, an Outlook plugin for subscribing to published calendars.
• Outlook2VCal - exports Outlook data to a single vCalendar file.
• iAppoint - exports Outlook data to .ics.
• Mozilla Sunbird
• Fun With Calendars
• iWebCal (a PHP viewer for .ics files)
• PHPiCalendar
• iCalibrate (CAM for iCal)
• iCal calling iTunes
• RSSiCal (RSS import)
• jical
• Enabling Outlook Users to view iCal Invitations