Qalculate

The library and command‑line tool provide a cross‑platform calculator capable of evaluating complex mathematical expressions, performing unit conversions, and handling symbolic operations such as differentiation, integration, and equation solving. It supports arbitrary‑precision rational and floating‑point numbers, complex and infinite values, uncertainty propagation, interval arithmetic, and mixed‑fraction output, while also offering RPN mode and extensive number‑base handling.

Designed for both casual and technical use, the software includes a user‑friendly interactive CLI with history, completion, and customizable settings, as well as GTK+ and Qt front‑ends. It can be integrated into other applications via the libqalculate API, and it is employed by various desktop environments and educational tools.

Installation requires standard development libraries (GMP, MPFR, libxml2, etc.) and follows a typical configure‑make‑install workflow. Documentation is provided both in‑package and online, covering command‑line options, API reference, and usage examples.