Open Source MS-DOS Calculators

4tH is a Forth compiler with a little difference. Instead of the standard Forth engine it features a conventional compiler. 4tH is a very small compiler that can create bytecode, C-embeddable bytecode, standalone executables, but also works fine as a scripting language. It supports about 95% of the ANS Forth CORE wordset and features conditional compilation, pipes, files, assertions, forward declarations, enumerations, structures, suspended execution, recursion, include files, etc. It comes with an RPN calculator, BASIC interpreter, line editor, preprocessor, compiler, decompiler, C-source generator, a virtual machine, and a multitasking environment.

Pc Calculator is a clever note and formula editor combined with an advanced and strong scientific calculator. Being an editor it is extremely user-friendly allowing all possible typing and other errors to be easily corrected and fast recalculated.

Modeline calculator designed to calculate low resolution modelines for CGA, EGA, and VGA arcade monitors, NTSC and PAL televisions, and multisync PC monitors. Supports X11, fb, and AdvanceMAME modeline formats.

kalc is a programmable scientific calculator, using RPN (Reverse Polish Notation). Its behaviour imitates a HP48/HP49 calculator. Works with real and complex numbers, unlimited size integers, arbitrary-precision real numbers and more.

Calculator++ is an Open source Scientific Calculator app designed to replace the standard Calculator app. Currently in MS-DOS Format.

Equalculator is an equation calculator. It is currently in the "pre-alpha" stage of development, so don't expect it to do miracles. You type in your equation, it will ask you for the variables and Voila!, it gives you the answer.

FoxCalc is a calculator with a text user interface (TUI), compiled for DOS. It supports a mouse, and uses the GMP library, therefore its results are highly accurate. FoxCalc is distributed as a zip FreeDOS package. That way, it can be easily installed using the FreeDOS package manager.

FreeDOS Reisdent Calculator -- programmer's TSR calculator.

Metrics calculator tool, with plugin support to easily adapt to any language

Ultimate Scientific Calculator (USC) is a program to perform calculations with extreme precision on both extremely large or small numbers, and provide too many built-in and user-defined functions and formulas.

rcal is an interactive calculator for DOS, that loosely mimics the behavior of "roller printing" calculators. It supports huge numbers, floating point and has extremely low hardware requirements.