Paul L. Bailey, Ph.D.
Open Source Software

This page contains links to some of my favorite open source programs. Open source software is often better than commercial software, and is FREE.
Visit the Open Source Initiative at

An advanced compression utility is 7-Zip

A powerful yet simple text editor is Notepad++

An excellent code comparison application is WinMerge

A great command line C compiler is Tiny C Compiler (TCC)

Geogebra allows the user to make geometric constructions and to graph functions. Visit Geogebra

GAP is a computer algebra system which concentrates on group theory, but also handles rings, fields, vector spaces, and so forth. It is powerful, syntactically elegant, and free (being open source). Documentation is included.
Dowload the most recent version of GAP at

TeX is a mathematical type setting language. The user creates a source file in any text editor, which is then compiled. The basic compiler is separate from the text editor. We recommend MiKTeX in conjunction with WinEdt.

First, download and install MiKTeX, obtained from
Next, download and install WinEdt, obtained from
Installation of WinEdt should find your version of MikTeX, so that the WinEdt editor/shell can compile. The compiler creates a .DVI file, which is then viewed using YAP (yet another previewer), printed, or converted to .PDF.
You may need a book to explain how to write the "code" which is compiled.
I learned from Math into TeX: a simple introduction to AMS-LATEX.
AMS-Latex is one of the brands of TeX; it is the one required by the AMS (American Mathematical Society) for article submission. MiKTeX is open-source (thus free); WinEdt was written by a math grad student to help him create his thesis, and he is still improving it. Send him the $30 he requests.

There is no reason to buy expensive database management systems like Oracle or Microsoft SQL Server, because the open source SQL database known as MySQL is just as good for most things, is faster, and is FREE. This is very easy to use; check it out if you have any inclination to store and/or analyze data.
Download the most recent version of MySQL at