I am a mathematician thinking about how to teach mathematics. The articles in this collection experiment with didactical ideas that I want to try out, e.g. hierarchical proofs, interactive animations, expandable/collapsible document structure, labeled equations, multi-use documents etc. A lot of the material is still raw and unpolished, also I am not a web designer so things might look weird or break. You're welcome to contact me via firstname.lastname@example.org.