Kalkulator
Kalkulator for Windows: the Mother of All Calculators, a Swiss Army knife for scientists, engineers and students.
http://www.wrotniak.net/works/kalkulator/

Ilient
SysAid Help Desk Software by Ilient.
http://www.ilient.com

Perl for System Administration
Perl for System Administration is aimed at all levels of administrators on the Unix, Windows NT, or MacOS platforms. Assuming only a little familiarity with Perl, it explores the pockets of administration where Perl can be most useful, including filesystem...
http://www.oreilly.com/catalog/perlsysadm/

Finite Mathematics
Covers transcendental functions, algebraic functions and the graphing of functions.
http://campus.northpark.edu/math/PreCalculus/TOC.html

Sibental
Query-Blaster assists with building parameterised stored queries and writes the VB/ASP functions to call them. Other products for SQL Server and system administration.
http://www.sibental.com

AcademicEdge
AcademicEdge web-based student information system software suite for Colleges and Universities. Now available as a Java/J2EE application.
http://www.academicedgeonline.com

Hyena
Provides Windows NT administrators a single, centralized interface for system management functions. Working with one or more domains, NT/2000 administration is simplified. Object and hierarchical list displays.
http://www.systemtools.com/hyena/

gecco
GNOME Extensible Configuration COnsole, goal: to provide central location to access system administration functions within GNOME environment.
http://gecco.sourceforge.net/

Miller, Lance
A personal page with examples of original PHP code. The site functions as a resume, but also displays code snippets and tutorials on linux and OS X administration.
http://www.lancemiller.org/

Friendly Pinger
Friendly Software
http://www.kilievich.com/