Teamup Calendar - Cloud-based calendaring using capability URL, application developed in Zurich, Switzerland.
Teem - Cloud-based meeting room booking system
Campaign Calendar - Campaign Calendar by Bracket Labs builds a marketing calendar from your Salesforce Campaigns.
Meetio Room - Meeting Room Booking System
ApPHP Calendar - ApPHP Calendar is a PHP calendar script that may be easily integrated and used with various PHP projects, such as schedulers, event, etc.
BOOKMEETINGROOM.COM - Book Meeting Room - Conference & Meeting Rooms Management