EssentialPIM - EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.
Meetio Room - Meeting Room Booking System
Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.
Resource Central - Meeting room & resource scheduling software for Outlook
Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.
Smartway2 - Book meeting rooms, desks & more via mobile/Outlook/desktop