I've been looking for some good video's about geogebra. It amazes me that such a powerfull tool is completely free and available for anyone. That said, I'm trying to build a free platform for my anyone who needs a litle more training and exercise regarding math. So I'd like to see a video where you'd explain a bit about how to create an applet that can be used for an online math course. Basically with input, validation and all that kind of stuff. Thanks for uploading all these video's!