PCalc - PCalc is the powerful choice for scientists, engineers, students, programmers, or indeed anybody...

SpeQ Mathematics - SpeQ is a small, extensive mathematics program with a simple, intuitive interface.

Calculator++ - Calculator++ is an advanced, modern and easy to use scientific calculator.

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

NumWorks - The graphing calculator that makes learning math easier.

Soulver - Soulver is a software application that functions as a calculator that allows you type a continuous stream of information rather than having to input data into multiple cells.