We take stock of the present position of compositional data analysis, of what has been achieved in the last 20 years, and
then make suggestions as to what may be sensible avenues of future research. We take an uncompromisingly applied mathematical
view, that the challenge of solving practical problems should motivate our theoretical research; and that any new theory should
be thoroughly investigated to see if it may provide answers to previously abandoned practical considerations.
Keywords simplex geometry - Hilbert and Euclidean space - subcomposition - regression - sample space - stay-in-the-simplex