It is extremely flexible and powerful, works and protects very well, great to confine servers and databases with it. You can have with it any security policies you have enough imagination to think up. Also, it seems having near no impact on performance, several percents at most.
It is also true that setting it up can be a permanent punishment well close to the bottom on the hell and automatic tools are not that good. audit2allow is often your the only friend.
Labs4Wikiversity was (still is?) the older attempt to provide public free encyclopedia with user-supplied interactive content. While the project aimed to create both infrastructure (MediaWiki server side plugin) and visualizations, the source code at SourceForge.net only contains some Java applets. These applets are well written and Ultrastudio.org uses them all. We are currently not aware how much Labs4Wikiversity itself is still alive. All contents of the source code are under GPL.
Somewhat strange that the system so powerful and complex only has one active developer. More likely there is something wrong/obsolete in analysis. Also, the license of this engine seems LGPL, not GPL that can be verified in the project site at http://jamwiki.org/. It is an excellent engine from the view point of stability and performance.
Looks like a great tool to test expressions before using them in your code. Regular expressions are kind of language and this is a great debugging tool that may save hours and days of debugging the application where these expressions are used.
After reviewing the code to feed this to Ultrastudio.org I would also say that it is in comparison to other applets very cleanly written, while of course not a lot of code is required for such a task.
This applet works, but it has very little interactivity, merely displaying the periodic table. It however does provide the enhanced details panel where it would be possible to give more details on an element that fit into the cell. Still, work needs to be done to add enough data for this feature to be efficient.