A nonlinear least squares fitting program that handles input errors or a covariance matrix on each axis. The curve fitting can use many curves simultaneously and stick them together with their parameters or points, in many dimensions.
http://www.prz.rzeszow.pl/~janand/
Calculator for basic matrix operations. A demo version download is available.
http://members.shaw.ca/mtx/matrix.htm
JAVA applet that allows mathematical online calculations.
http://calculadora.edu365.com/
Evaluates mathematical expressions. Includes history feature, function-pick window, and help. Variables and hex numbers are also supported.
http://www.mujweb.cz/www/mirza
Guide on how to create a simple command-line calculator for the tcsh, bash and zsh shells.
http://home3.inet.tele.dk/frda/src/calc_tip.html
Write complex equations, assign results to variables, execute multiple equations using script files, and simulate fixed word length effects.
http://www.megpeg.webcentral.com.au/megpegcalc/
A realistic ten key calculator designed by a CPA.
http://www.mytenkey.com/
HP-15C scientific emulator for Pocket PC.
http://www.lygea.com/pocket15cdetail.htm