Normala.hr is an initiative of a non-profit organization of teachers of mathematics in Croatia, focused on teaching mathematics in elementary and secondary schools. They use XWiki as a wiki platform, and GeoGebra applets for mathematical concepts illustration. GeoGebra is an Open Source "dynamic mathematics software for schools that joins geometry, algebra and calculus". Look for example at the cosinus function graph (drag the purple point around the circle to draw the function) or the hyperbole construction applet (you can play with the sliders to draw the hyperbole) examples on normala.hr.

The integration with XWiki is very smooth, thanks to the fact XWiki supports plain HTML in its documents. The easiest way to integrate GeoGebra in XWiki is to attach the GeoGebra .ggb file to a wiki document, and use this code snippet to display the applet.

Conclusion : GeoGebra + XWiki = Great combo for educational wikis !