My apologies. I am quite busy for the past two weeks, and looks like I am going to be busy until the first week of March. Anyway, for those who had not visited Mathematics and Multimedia recently, the GeoGebra Essentials Series had already been updated to version 4.0.
The first 10 tutorials in the GeoGebra Intermediate Tutorial Series were also updated last month. I hope this will help those who want to learn the new version of GeoGebra.
I am going to resume the revision next week.