Qalculate! is a multi-purpose cross-platform desktop calculator. It is simple to use but provides power and versatility normally reserved for complicated math packages, as well as useful tools for everyday needs (such as currency conversion and percent calculation).
Scientific calculator with arbitrary precision and portrait and landscape mode. Fraction and periodic numbers support. Looks like a real calculator! The calculator has up to 100 digits of significand and 9 digits of exponent.
HiPER Scientific Calculator Features
PCalc is the powerful choice for scientists, engineers, students, programmers, or indeed anybody looking for a feature rich calculator. It includes an optional RPN mode and multi-line display, a choice of button layouts, an extensive set of unit conversions and constants, a...
XCALC is my little RPN calculator completely free to use, and still downloadable. XCALC is now a DEAD project. No work has been done on this project since 2012, and nothing more will be done either.Discontinued
XCALC is now a DEAD project per homepage, but it is still downloadable.
galculator is a GTK 2 / GTK 3 based calculator with ordinary notation/reverse Polish notation (RPN), a formula entry mode, different number bases (DEC, HEX, OCT, BIN) and different units of angular measure (DEG, RAD, GRAD).Discontinued
Reported as no longer to be updated/developed by the developer : https://github.com/galculator/galculator/issues/37So far no forks have appeared.
Excalibur for Windows 32-bit version is a freeware full featured RPN-only calculator. This is a serious calculator for serious users. Excalibur takes up a small amount of resources for all it does so well.
The website is unavailable, but the app can still be downloaded from third-party websites.
Hypatia is a text-based programmable scientific calculator for Windows that uses its own enhanced version of RPN (Reverse Polish Notation). Hypatia is free, open source, fully portable, has a very small footprint, and can be run from the Windows desktop, the PowerShell, or from...
Hypatia RPN Calculator Features