## Ideas for Software to Integrate with Sage

This is a list of programs and packages for mathematics that might possibly be included with or at least have an interface with Sage someday.

Sums of Squares via Macaulay2. This is related to http://www.cds.caltech.edu/sostools/

http://www.4ti2.de/ -- A software package for algebraic, geometric and combinatorial problems on linear spaces; I (=william) have made optional Sage packages for this and written a very preliminary interface. This depends on a linear programming package, which Sage needs.

http://www.gnu.org/software/glpk/ -- Linear programming. It's 1MB, and very easy to build.

http://www-sop.inria.fr/galaad/software/synaps/ -- It's a GPL'd C++ library for doing numerical and algebraic stuff together and seems mature. It requires FORTRAN and is very hard to build. I skimmed some source code and it seemed relatively readable at first glance, and maybe there is something useful in there. It's focused on numerical over algebraic.

http://yacas.sourceforge.net/ -- YACAS is an easy to use, general purpose Computer Algebra System. It uses its own programming language (a sort of Lisp dialect) designed for symbolic as well as arbitrary-precision numerical computations (it can be linked to GMP library). YACAS comes with extensive documentation (320+ pages) covering the scripting language, the functionality that is already implemented in the system, and the algorithms used.

Bergman (non-commutative Groebner bases).

kseg (dynamic Euclidean geometry, a la Geometer's Sketchpad; relevant for educational users). (This is GPLV2+)

scmutils, an MIT-Scheme package for symbolic manipulation, mostly with differential geometry. Created for the SICM: Structure and Interpretation of Classical Mechanics course

blad: BLAD is an acronym standing for Bibliothèques Lilloises d'Algèbre Différentielle. BLAD is actually sort of a standalone C analogue of the MAPLE diffalg package. BLAD is LGPL.

## Software that is free and tries to do what Sage does

http://www.mathemagix.org/mmxweb/web/welcome.en.html -- Their overall goal is very similar to Sage's. However, they make different design choices than we have with Sage in almost every way:

They build everything around texmacs, which is a "beautiful" yet aggravating program.

- They use C++ *very* very heavily.
- They write their own new custom interpreter language for mathematics (though they describe it as general purpose, and strongly emphasize it shouldn't be for just math).