With some interest exploring new technique and new theory, the use of Tcl with Tk has proven many times to be the right choice for quick prototyping and demos. Quite often, one does not really know where a given track will finally go: simplicity, flexibility, extensibility is what is being sought so that changing everything is neither frustrating nor painful.
I have used Tcl and C/C++ with Critcl to implement ciphers and wavelet transforms. Whilst a simplified version of the later is publicly available on the net - see YawTcl and Wavelet Transforms - all the legal stuff has still to be sorted out before the ciphers are made public.