From DT Online
Mathematical Etudes (Etudes = French for Studies) is an excellent resource supported by the Russian Academy of Science.
The stated aim of Mathematical Etudes is to develop Russian traditions in the popularisation of mathematics. The site presents 3D animations which demonstrate aspects of mathematics and its applications in and exciting and interesting way.
Each animation is accompanied with explanations which can be followed by pupils and students - even though scientists so far may have not have solved some of them!