SpeedCrunch - SpeedCrunch. SpeedCrunch is a high-precision scientific calculator featuring a fast, keyboard-driven user interface. It is free and open-source software, licensed under the GPL. Download Documentation Donate .

Kalk Calculator - Powerful calculator application for Linux mobile and desktop devices

WolframAlpha - WolframAlpha brings expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels.

NumWorks - The graphing calculator that makes learning math easier.

Qalculate! - Qalculate! is a multiplatform multi-purpose desktop calculator.

Calculairum - Descriptive, Editable, Gesture-Based & Voice Controlled Calculator