Online Java calculator for matrix operations.
http://www.ifrance.com/mathematics/index_gb.htm
Javascript calculator with basic scientific functions.
http://www.ScientificCalculator.com/
Conversion program that gives the day of the week for a given date.
http://www.hermetic.ch/cal_sw/calconv/calconv.htm
Javascript scientific calculator using RPN.
http://mypage.bluewin.ch/a-z/cusipage/scicalc.html
Scientific calculator.
http://www.romanlab.com/1stcalc/
Calculates expessions using unit conversion and interval arithmetic. Supports numeric values with units and calculations using units, values with errors and interval arithmetics. Windows32. Free trial download.
http://www.tiksiland.com/~cb
A freeware awarded scientific RPN calculator for Windows with many functions and customizable user interface
http://www.speech.kth.se/calculator
Java applet online calculator.
http://www.mathpad.com/public/htmls/main/left/calc/CalcInfo.html