A collection of interactive learning activities (interactivities) and simulations. If you try just one of them, check out the "Scale of the Universe" interactivity.
OpenSimulator is an open source multi-platform, multi-user 3D application server. It can be used to create a virtual environment (or world) which can be accessed through a variety of clients, on multiple protocols.
EcoMUVE is an exciting new curriculum research project at the Harvard Graduate School of Education that uses immersive virtual environments to teach middle school students about ecosystems and causal patterns
One of my favourite learning objects of all time. I watched it being created by the late Jonathan Swallow with support from then-workstudy student Brad Carson when I was running the Interactive Learning Centre at Trent U. I loved how Jonathan was able to take something in the prof's head and reconceptualize it / build it for students.