FortranCalculus (Prose, Slang) Website for Sale; Automatic Differentiation & Operator Overloading

My website,, is up for grabs. It consists of some apps that demo what an Optimization compiler can do for you. The compiler, FortranCalculus (FC), is based on Automatic Differentiation (AD) coupled with Operator Overloading (OO). FC comes from NASA’s Apollo Space Project in the 1960s where TRW (Systems ?), Inc. was hired to create a faster compiler.


TRW used AD & OO to create, 100 man-years, the Slang compiler that dropped solving NASA’s problem-solution timing from years to a day or two.

Next, Prose compiler was the first industrial compiler using AD & OO in 1974 and it required another 100 man-years to develop. Prose was spread over Time-Sharing Control Data Corp. (CDC) computer networks.

Today, FC compiler was developed ~1990 and available for free along with manuals from our, Optimal Design Enterprise (ODE), website.


cPanel, web host plattform shows:
• 400+ visitors / day;
• 5+ visits / visitor; and,
• 50-100 Apps downloaded / day / App;

ODE business:

Google Estimates our website should bring in $5k / month.

Income Problem for Today:

  1. How to get income from today’s traffic; ie. 400+ visitors / day that will provide enough funds for:
    1a. Cover website server fees; ~$250 / year today.
    1b. Cover owner’s income needs today.

Income Problem for tomorrow:
2. How to bring in income from selling / renting / training folks using “continuous modeling” simulation vs. optimization solutions? For example:
2a. Our Match-n-freq App to Electrical Engineering (EE) professors who teach Filter designs to their students.
2a1. Worth to a student is a solution vs. the optimal solution; time savings ~1 to 12 months on a computer.

Other targets include:
2a2. “Filsyn software” company
2a3. “Compact software” company, Compact Software - Wikipedia
2a4. Any other EE filter design computer programs
2a5. Matlab, Mathematica, MACSYMA, MathCAD, & ADIFOR (the only other AD based language)

  1. “Process Control” & “continuous modeling” internet search should lead to other marketing fields; eg., Oil Refineries worth billions to companies.

Applications on website:

CurvFit™ is another improved productivity example do to using Calculus (level) programming … ie. minutes to solve, days or years to understand solution and what it implies (e.g. wrong model, sampling rate error, etc.). Helps learn 1) whether math model is good for given data; 2) convergence implies a reasonable solution; 3) how to select new starting initial parameter values. See comments in EX*.? files for ideas on how to converge via solvers. Interpolation, extrapolation, & Hardcopy Plot options are now available.

Industry problems with solutions over the past fifty plus years have been put into a textbook to show the power of Calculus (level) Problem-Solving. The textbook is on our website at eBook on Engineering Design Optimization using Calculus level Methods, A Casebook Approach . The software architect behind Calculus Compilers is Joe Thames (read about Joe on our About page).

FC-Compiler™, the FortranCalculus Compiler, Alpha version

FC-Compiler™ is a (free) Calculus (level) Compiler that simplifies Tweaking parameters in ones math model. The FortranCalculus (FC) language is for math modeling, simulation, and optimization. FC is based on Automatic Differentiation that simplifies computer code to an absolute minimum; i.e., a mathematical model, constraints, and the objective (function) definition. Minimizing the amount of code allows the user to concentrate on the science or engineering problem at hand and not on the (numerical) process requirements to achieve an optimum solution. Download at FortranCalculus Compiler: Solves Algebraic Equations through Ordinary Differential Equations.

FC-Compiler™ has many (50+) example problems with output (see ‘Demos’ on main menu) for viewing and getting ideas on solving your own problems. These are improved productivity examples do to using Calculus (level) Problem-Solving. Please share this Calculus Problem-Solving tool with your friends. Thanks!

NASA’s Apollo Space team developed the first Calculus (level) language, Slang, to solve complex math equations with minimum effort and time. Slang was renamed Prose and was introduced to the industrial world in 1974. Today, a (free) Windows version is available for their FortranCalculus language/compiler.

Match-n-freq™, a Matched-Filter (Transfer Function … Poles/Zeroes) Design Application

Match-n-freq™ is a (free) Pulse Shaping Filter program that finds the pole-zero locations of a transfer function, H(s), for a matched-filter design. H(s) equals a -desired- signal (Yout) divided by a given input signal (Yin). Both Yout and Yin are functions of frequency. Download at Matched Filter, Kalman Filter, Nonlinear Filter, Signal Processing, Transfer Function, Electrical Filter .

H(s) has equal sidelobe peak amplitudes in a Bode plot; i.e., Peak i = Peak j for all i, j.

Group delay may also be calculated to compliment a given data set, thus, providing a flat group delay. Minimizing Intersymbol Interference in a read/write channel for disc drives by shaping and slimming an isolated readback pulse was the main objective for writing this program.

Make your own ‘transfer function’ app: have a function you want to try? See the Match-n-freq’s source code (included in FC-Compiler-install.exe) … FC-Compiler\demos\nesting\filter.* files. Modify these transfer function to fit your desired function(s). Download the free FC-Compiler™ that you will need to re-compile your version of your ‘Match-n-freq’ program.

For more info, see Kost, R. and P. Brubaker; ‘Arbitrary equalization with simple LC structures’; IEEE Transactions on Magnetics, Nov. 1981, pp 3346-3348 or visit Pulse Slimming for Magnetic Recording, Intersymbol Interference, Modeling & Simulation . Another improved productivity example do to using Calculus (level) Problem-Solving.

ODEcalc™, Differential Equation (ODE) Calculator!

Solves Nonlinear ODEs. State your equation, boundary/initial value conditions and it solves your problem!

SpectrumSolvers™, a Spectral Estimation Application

Which estimator is best for your job? SpectrumSolvers™ (free) program helps Find best Spectral Estimation Method for a Power Spectral Density plot. A menu of 10+ spectral estimators from Steven Kay’s textbook ‘Modern Spectral Estimation’ 1988 is available to choose from. The results differ dramatically from one estimator to another. Plus, varying input parameters and/or number of points may provide discrepancies. Observe how zero padding effects your results. Manufacturing companies take note! Some estimators can detect signals 50 to 100 dB from main signal. See documented example! The unwritten rule of ‘30 dB is okay’ (i.e. hidden) is no longer true. Download at SpectrumSolvers: Compare 13 Spectral Estimation Algorithms, Spectral Estimation Methods, Signal Analysis, Signal Processing .

Add your own ‘estimator’ to your own ‘SpectrumSolvers’ app: have an algorithm/method/solver you want to try? See the PSDcalc_for.dll’s source code (included in SpectrumSolvers-install.exe) … spectrumSolvers\for*.f90 files. Modify these algorithms to fit your desire.


Have you seen movie Hidden Figures, if you haven’t seen it, you should. It may help understand the communication problem between different types of people; e.g. NASA’s Engineers, Scientists, and Mathematicians. The movie shows engineers trying to solve some equations and getting no where fast! A mathematician comes along and solves the problem. But numbers say little to engineers. Near the movie’s end, the mathematician draws a graph showing a solution. The engineers finally get the ‘picture’ of what the equations are trying to say to them. Remember, a picture is worth a 1,000 words, right?

Phil Brubaker
Mathematical Engineer / Electrical Engineer / Author / STEM Speaker
Oregon State University '67

What did the movie inform you about scientists?!

While we’re on the subjects of websites, Walt Brainerds’s old site still seems to be dormant. Pity.


I think that @greenrongreen is keeping Walt’s site alive.

1 Like

Fine as long as he does it on another web page, NOT mine!
His ad is distracting from my topic of Automatic Differential (AD) and the 3 AD compiler / languages that I have been promoting for 30+ years.

@OptimalDesigns Fortran Discourse is for Fortran discussion. You’re welcome to respectfully promote your website here because it’s on the topic of Fortran, however, this doesn’t make it your page that prohibits others from discussing other Fortran websites. I deem the posts on topic and otherwise appropriate.

Okay, may I speak with a Fortran supervisor please.

Does the sale of the website include the FortranCalculus compiler source code? Seems like an interesting domain-specific language for optimization.

Is the FortranCalculus compiler only available for Windows? I don’t own a Windows computer, and I suspect this is true for many others as well.

Also: I have no means to buy the website, and am just curious. I suspect you would find more interest in buying the website from previous customers of yours than on a Fortran enthusiast forum like this. If your intention is to ensure this work continues, I think you’d probably find that open sourcing the compiler and other code would be more effective than selling the website, as well.

200-man years of work! No way

Just Windows but there is a Linux version in the works. But, other Compilers were sold to individual companies e.g. Varian, Hansen Way, Palo Alto, CA 94303 (last address I have… 1980s. The last Time-Sharing version (~1985) was sold to a company in Mexico. There were some ~50 versions sold with varying names all used Synthetic Calculus, key word. Hope this helped :slightly_smiling_face:

For what it’s worth, I’m skeptical that you’ll find someone interested in buying a website for a particular software without also selling the source code for that software. I can understand wanting to get granular about what’s being sold. But look at it from the perspective of a buyer. They won’t be able to improve the core product without the source code.

Good luck!

I’ll also observe that the domain name is rather generic and I’d be doubtful there’s much interest in just the web site.