DreamCalc Graphing Calculator
DreamCalc is the smarter alternative to a hand-held Graphing Calculator for your PC or laptop! You'll get the intuitive feel and productivity of using a professional hand-held, but one which adapts to your way of working. With DreamCalc, you'll be able to graph functions and plot list data more... It is a "must" for Business, Science, Engineering and Education. ... DreamCalc also offers you a full range of scientific functions, statistics, complex numbers, base-n logic, unit conversions, built-in constants and a powerful polynomial solver.
http://www.dreamcalc.com/downloads/dc3g_setup.exe - 3Mb - Download - Screenshot

pSogol
Math Asst. , Calculator, and Hypertext Notepad for Scientists and Engineers using Pocket PC 2003. Assists with calculating networks of formulae, dynamic simulation, differential and linear equation solution, multiple equations and unknowns, builtin script language. ... Useful for engineering and science computations, trying out algorithms, plotting results, quantitative brain-storming, and documenting problem solutions. ... User acquires or creates application files called webs to solve particular problems of interest.
http://www.codelode.com/Sogol/pSogol/PSOGOL12.exe - 2Mb - Download - Screenshot

Dicom
Q. What it does? Dicom calculates, converts and computes. The first ever computing tool that deals with dimensions of physical quantities in mathematical expression, Dicom, has the answer to expression like: 30 mi. /h. +6 ft. /s. +15. 24 m. /s. to ft. ... Dicom can be useful in many areas, especially in science and engineering. ... What about Dicom Document? ... Dicom document is rich text formatted (RTF) file, which is portable across many applications and platforms. ... And as stated already, it has a built in rich text editor that can process texts as well as dimensional expressions.
http://www.knowbotron.com/download/dicom40install.zip - 254Kb - Download - Screenshot

Unit Converter Pro
Unit Converter Pro is a handy utility for students, teachers, and practitioners in engineering, physics, sciences, and technical subjects. It can quickly convert more than 1400 different units in 76 categories. It contains the most important conversion factors for length, area, volume, mass,... No restrictions in the shareware version. ... The categories include: Mass, Length, Time, and Volume. ... Acceleration - Linear, Area, Data Storage, Data Transfer, Energy, Flow, Force, Numbers, Power, Pressure, Temperature, Velocity, Acceleration - Angular, Angle, Calorific Value, Concentration -...
http://www.unitconverterpro.com/ucpro.exe - 874Kb - Download - Screenshot