Conversion program that gives the day of the week for a given date.
http://www.hermetic.ch/cal_sw/calconv/calconv.htm
C code for orientation and incircle tests using adaptive-precision floating-point arithmetic
http://www.cs.cmu.edu/~quake/robust.html
Uses wireless networking to synchronize log databases across all stations. Includes technical information and download.
http://www.qsl.net/wb6zqz/fdlog/
Feesa for Flow assurance, simulation and optimisation of oil & gas product systems. Field planning, fluid engineering, multiphase flow, slugging and transient analysis.
http://www.feesa.net/sim_services.htm
Computer algebra system that does arithmetic of arbitrarily long integers and fractions, symbolic calculations, graphics, and other numerical calculations. Free download. Documentation.
http://www.bway.net/~lewis/
High precision calculator with unit and radix converters.
http://www.haxial.com/products/calculator/
A JavaScript Calculator that adds, subtracts and multiplies fairly large numbers. Functions are added in my copious free time.
http://www.petting-zoo.org/Calculator.html
mcalcdos is a free command line linear algebra calculator capable of matrix, vector and polynomial operations in real and complex fields.
http://www.angelfire.com/space/matrixcalc/
Calculations for dipole, 3-element Yagi, 7/8, quarter, half, and full wavelength.
http://bfn.org/~bn589/antenna.html
Online calculator, written in Java. Includes Square root button and number memory. Source code can be downloaded.
http://www.df.lth.se/~mikaelb/pocketcalc-enu.shtml