OpenBoard - The OpenBoard software is an interactive white board software.
Smoothboard Air - Smoothboard Air is a collaborative interactive whiteboard application for iPads and Android devices that revolutionizes interaction in lecture rooms.
Surface Studio - A brilliant screen for your ideas, from Microsoft
Groupboard - Free collaborative online whiteboard, web conferencing and online tutoring software that can be embedded in your own website. Used by many online tutors, schools and universities.
Twiddla - Mark up websites, graphics, and photos, or start brainstorming on a blank canvas.
RealtimeBoard - RealtimeBoard is an online collaboration software created as a team collaboration and online brainstorming tool. It's super easy to use & free!