The slides were created using a software program called 'Mathematica'. I like it because it makes visualization and interaction very easy. The lecture notes are an html version of the slides, but unfortunately it is no longer possible to interact with the demonstrations. The slides can be viewed here.
However, on the Wolfram Demonstrations Project Website, you can find a lot of demonstrations similar to what I showed in the lecture. Besides that, you can play around with Wolfram|Alpha, a sort of search engine that also let's you do a lot of math.