Ruvenss Calculator - Simple yet very effective calculator with print capabilities and log registration.
Calculist - The open-source, web-based thinking tool that facilitates effective thinking for solving problems.
PCalc - PCalc is the powerful choice for scientists, engineers, students, programmers, or indeed anybody...
Numi App - Numi is a beautiful text calculator for Mac.
OpalCalc - OpalCalc is a brand new type of calculator for the PC.
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.