Matlab contains multiple libraries for handling sparse data. These can report very detailed internal info.
Matlab's MEX API contains numerous undocumented functions, that can be extremely useful.
Matlab exposes undocumented info about its internal math libraries; these libraries can be upgraded manually.
JGit source-control integration package can easily be integrated in Matlab.
Waterloo graphics can be updated very quickly in Matlab, enabling plot animation; web deployment of the graphics is also possible.