SpeQ Mathematics - SpeQ is a small, extensive mathematics program with a simple, intuitive interface.
Calculator-online.net - The 100% free and reliable online calculators that help you to solve any calculation-related problems and provides you with the precise measurements.
Qalculate! - Qalculate! is a multiplatform multi-purpose desktop calculator.
Calculatored - Calculatored presents the variety of calculation tools. Whether you are a Student, Teacher or a Businessmen you can find the best tool for your requirement.
NumWorks - The graphing calculator that makes learning math easier.
Calculator OSX App - Real Time.