(!) Note that even though most planned features are in place and I personally find it highly stable and reliable in everyday use, Qalculate! definitely needs more testing and no guarantees whatsoever are given.
With that said, you are welcome to download the latest version of Qalculate! and report any bugs you find.
Qalculate! version 3.0.0 (source code):
Graphical user interface requirements:
Text interface requirements:
Installer for Windows:
A binary snap package for Linux, with all dependencies included, is available at snapcraft.io/qalculate for those using a slow moving GNU/Linux distribution (install with the command "sudo snap install qalculate").
A Mac OS X port is available here:
Qalculate! at MacPorts.
Old versions can be found at the project page for libqalculate and qalculate-gtk. Ancient versions are available at the old project page at sourceforge.net.
Qalculate! KDE Plasma widget