XWPL is an X based tool to examine one-dimensional real-valued signals using
wavelets and wavelet packets. It has been designed to be as easy to use as
possible for beginners. It is intended more as an educational and exploratory
tool than as a numerical analysis program, even though it uses fast, optimized
wavelet and wavelet packet transforms. NOT USING BECAUSE IT ISN’T SPECIFICALLY RELATED TO DATA COMPRESSION.

http://pascal.math.yale.edu/pub/wavelets/software/xwpl/