A number of people have contributed to this document, either with helpful general remarks or corrections or amplifications on points of detail. Where their contribution was precisely localisable -- in particular where I have merely sub-edited their comments into place -- they are also acknowledged at the appropriate specific points in the text.
Sergio.Gelato@Durham.ac.uk) added remarks about optimizing C, and compiler switches.
firstname.lastname@example.org) added pointers to model atmosphere codes.
email@example.com). Pointers to model atmospheres.
firstname.lastname@example.org) made a number of points about my coverage of Fortran, and several insightful remarks about numerical programming.
Robin.Williams@astro.cf.ac.uk) general comments, and information about Alpha switches.