Updated: 12/29/2005
Calculators
Calculators, 17000
Yes, links to over 17,000 calculators here for engineering, physics, statistics, science. Mostly online Java calculators. [Report a dead link]
http://www-sci.lib.uci.edu/HSG/RefCalculators1.html

DazyCalc
Expression solver with scripting, 1025 x 768 screen resolution required, hex-dec-bin ops, equation graphing, loan calc, electronic formula functions. [Report a dead link]
http://www.dazyweblabs.com/shannonsoft/page3.html
[Screenshot]

Easy Grapher
Plot graphs of one or more series of functions or datapoints. Features: Store/Load graphs in XML format; save graph as scalable EMF image or web ready PNG image; Polynomial curve fitting; zoom and pan. [Report a dead link]
http://jansfreeware.com/jftools.htm#easygrapher

Equalizer
A scientific calculator with skins. It calculates line-oriented expressions. Very good. [Report a dead link]
http://members.nbci.com/_XMCM/imkobi/eq/index.html

ESB Calc
Scientific calculator. It provides Precedence, Brackets, Functions, Memory, Clipboard Support, Result History, Physical Constants and more. Includes a rolling tape to show all your calculations. Also at http://freestatistics.altervista.org/math.php. Homepage at http://www.esbconsult.com/esbcalc/esbcalc.html. [Report a dead link]
http://www.sover.net/~wysiwygx/Desktop1.html

Euler , Editor's Pick
A mathematical expression solver. Euler is a numerical laboratory with a programming language. The system can handle real, complex and interval numbers, vectors and matrices. It can produce 2D/3D plots. Included is a programming language. All versions are freeware and open source under the GNU general license. Euler is not a MatLab clone, but similar to this program. [Report a dead link]
http://mathsrv.ku-eichstaett.de/MGF/homes/grothmann/euler/

Excalc
Expression evaluator, evaluates complex expressions like: ATN{(5.783E+05-1.345E+05)/(3.255E-03-2.288E-03)} [Report a dead link]
http://homepage3.nifty.com/piazza/tek/sub/excalc.htm

Free math calculators
A whole handful of freeware math calculators. [Report a dead link]
http://freestatistics.altervista.org/math.php

FreeCalc (Moffsoft)
Calculator with running "tape". Has memory, sqroot, remembers position, can clear tape, digit grouping, more. [Report a dead link]
http://www.moffsoft.com/freecalc.htm

Frigate calc
Multiline calculator with functions. [Report a dead link]
http://www.winfrigate.com/calculator.htm
[Screenshot]

Graph calc
Graphs equations. [Report a dead link]
http://www.freeware-downloads.com/business.htm

Graph Paper
Working with graph paper is very very easy! Press Ctrl+F to display the Function window. Here you are supposed to describe y as a function of x. Erase whatever is already here, and type y=1/(1+x*x). Click on Draw. You will get a bell shaped curve. You can click your mouse inside the graph window and drag to slide the graph paper and explore more of the function. [Report a dead link]
http://www.geocities.com/hirak_99/goodies/graph.html
[Screenshot]

Graphmatica
A powerful, easy-to-use, equation plotter with numerical and calculus features. Graph Cartesian functions, relations, and inequalities, plus polar, parametric, and ordinary differential equations. Up to 25 graphs on screen at once. Offers copy to clipboard (bitmap and WMF), Button Bar, on-line help and demo files. X axis is always a factor of pi. [Report a dead link]
http://www8.pair.com/ksoft/
[Screenshot]

Graphs , 146kb
Enter a 2d equation and it will graph it in 3d. [Report a dead link]
http://www.sulaco.co.za/downloads.htm
[Screenshot]

Kyplot
Spreadsheet, math plotting tool with statistic support. [Report a dead link]
http://www.woundedmoon.org/win32/kyplot.html

MathGV
MathGV(tm) is a mathematical function graphing software program for Windows 95/98/ME, NT4, 2000 and XP. It can plot 2 dimensional, parametric, polar, and 3 dimension functions. 1. Plots 5 function types; 2D Cartesian (X, Y), parametric, polar, 3D Cartesian (X,Y,Z), 2D function rotated into 3 dimensions. 2. Graphs can contain multiple functions. 3. All graphs are drawn on resizable bitmaps, and displayed in scrolling windows. 4. Graph bitmaps can be copied and pasted into other programs, or saved to disk. 5. Multiple document interface (MDI) allows for simultaneous viewing of multiple graphs. 6. Can calculate negative numbers to fractional powers. 7. Function calculator that can give decimal or fractional results. 8. All changes take effect immediately after they are made. 9. Use tool bar buttons to zoom, rotate, and page up, down, left, right. 10. Graphs can be saved in bitmap (bmp), jpg or MathGV format. 11. Label tool bar for drawing, lines, free hand lines, rectangles, circles, round rectangles, flood fills, and text. 12. Labels can be selected, dragged, dropped, resized, added and deleted on any graph at any time. [Report a dead link]
http://www.mathgv.com/
[Screenshot]

Mathomatic
Mathomatic is a small, portable symbolic math program that can automatically solve, simplify, differentiate, combine, and compare algebraic equations, perform polynomial and complex arithmetic, etc. The C source code is available for free on this web page for a UNIX/Linux version. This is a console mode application that compiles and installs easily. http://www.lightlink.com/computer/math/, www.mathomatic.com. [Report a dead link]
http://www.lightlink.com/computer/math/

Pcalc
Solves equations with many built-in functions. [Report a dead link]
http://www.analogx.com/contents/download/program/pcalc.htm
[Screenshot]

PrestoPlot , Editor's Pick
Scatter plot, line plot, bar chart, linear and log charts, vector plot, error bars, discrete difference derivatives, integration, histograms, data set stats, data import from multi-column ascii files, scripting, command line options, user-defined annotations, multiple plots per graph, zoom, move and resize graph, print to any windows printer, copy graphs to clipboard, export graphs as BMP and PNG files. Animate plots. [Report a dead link]
http://lancelot.bio.cornell.edu/jason/
[Screenshot]

S-Calc
Scientific expression calculator. [Report a dead link]
http://www.geocities.com/satol/scalc.html
[Screenshot]

Sicyon
Expression evaluator calculator. [Report a dead link]
http://www.sicyon.com/
[Screenshot]

SmartSum Calculator
Talking adding machine/calculator.
- a scrollable "tally roll" ;
- you can go back and correct entries; insert and delete entries;
- save and re-load calculations;
- print the tally roll with choice of fonts;
- add comments to the tally roll and individual entries;
- check off entries;
- produce subtotals;
- automatic sales-tax (VAT) calculations,
- use 10 memories;
- write user-programmable macros;
- replace the digit vocalisation with your own etc. etc. [Report a dead link]
http://www.smartcode.com/smartsum/index.htm

Time Calculator , 26kb
Add, subtract, multiply, or divide time values. Also convert from fractional to decimal times. [Report a dead link]
http://www.geocities.com/knight_armour/descrp.html

Yacas
YACAS means "Yet Another Computer Algebra System" and it can maniuplate algebraic expressions to produce symbolic results. For example, if you enter Simplify((x-2)*(x+3)*(x+5)) you get: x^3+6*x^2-x-30. Because it works at the symbolic level, it can also manipulate ugly fractional math problems... When you enter 2/13+2/17, you get 60/221. [Report a dead link]
http://sourceforge.net/projects/yacas/