For those of you who want source code for numerical programming, here is some. The code is used in the well known Numerical Recipes series of books. The code is in Fortran and C and is well tested and debugged.
Of course, if you look on the web, these days, you could probably find equivalent code from reputable sources. But one selling point of the CD is its convenience. Against this is its price. Remember that the marginal cost of this CD with its packaging is pretty small. Only a few dollars. The price is a rip off.