Qalculate! is an arbitrary precision cross-platform software calculator. It supports complex mathematical operations and concepts such as differentiation, integration, data plotting, and unit conversion. It is a free and open-source software released under GPL v2.
Qalculate! supports common mathematical functions and operations, multiple bases, autocompletion, complex numbers, infinite numbers, arrays and matrices, variables, mathematical and physical constants, user-defined functions, symbolic derivation and integration, solving of equations involving unknowns, uncertainty propagation using interval arithmetic, plotting using Gnuplot, unit and currency conversion and dimensional analysis, and provides a periodic table of elements, as well as several functions for computer science, such as character encoding and bitwise operations.
It provides four interfaces: two GUIs, one using GTK (<code>qalculate-gtk</code>) and another using Qt (<code>qalculate-qt</code>), a library for use in other programs (<code>libqalculate</code>), and a CLI program for use in a terminal (<code>qalc</code>).