SAGE

(which stands for ‘Software for Algebra and Geometry

Experimentation’) includes and offers an interface to GAP, Singular,

Maxima and even PARI as

well as an interface to other packages such as Maple, Magma and

Mathematica (see here

for a full list of its features). More importantly, Sage offers a binary

for both PPC and Intel-Macs! I did check this out and it runs without

problems, in fact, after this initial check I installed from the sources

on my MacBook Pro and after one hour of compiling I did have working

(though not full) versions of GAP, Maxima and Singular. At first I

was a bit worried that only small subsets of the three systems were

installed, but it is quite easy to extend your Sage with additional

packages. From the Unix-prompt do a `sage -optional`

and you will get a list of all (additional) packages you have already

installed and those available for installation. SAGE is pretty well

documented with tutorials and reference manual to be found here. Even if you do not want to learn (yet) the Sage-commands but just

want to continue using the programs under its hood, this is pretty easy.

For example, to get to Maxima, you only have to type

`!maxima`

from the sage-prompt to open up a maxima-session

(and similarly for Gap and Singular).

Bill

Schelter’s Affine-package is not included, but you can load and install

it from the maxima-prompt by `load("affine.lisp");`

but some

commands such as ‘fast_central_elements’ do not seem to

work as expected (or maybe I forgot the drill over the years, I’ll try

it out again).