Recently, some people asked how to perform calculations in
(non-commutative) algebras, for example Clifford algebras
http://www.math.utexas.edu/pipermail/maxima/2003/004049.html
or quaternions (which happens to be a special case of the former)
http://www.math.utexas.edu/pipermail/maxima/2003/004130.html
The canonical answer to this ought to be: Just use Schelter's `affine'
package. Alas, a long time ago I announced to check it in
http://www.math.utexas.edu/pipermail/maxima/2002/002570.html
but I haven't done this yet. So here is my plan: I put Schelter's
original distribution
ftp://ftp.ma.utexas.edu/pub/maxima/affine.tgz
in CVS under share/affine, then I apply my patch (which has been
available for some time now, see the message cited above) piecemeal,
by "themes". I think that in a week or so things should be reasonably
functional in CVS.
Note that `affine' also contains rewrites of some parts of core Maxima
(notably a `new-rat' module, which, however, follows the classical
GENVAR/VARLIST paradigm). This means that, in the long run, it might
be preferable to replace some parts of core Maxima by corresponding
parts of `affine'.
Wolfgang