CCalc

CCalc is a calculator with syntax similar to the C programming language. Unlike the Windows calculator that pretends to be a calculator, CCalc pretends to be a computer. Actually, CCalc is a computer in that it can be programmed.

CCalc inputs a program, compiles it to an intermediate form, and interprets the intermediate code. As a result, CCalc compiles instantaneously and executes at approximately 1/10 the speed of a native compiler. For simple calculations, CCalc requires the same number of keystrokes as a regular calculator.

I wrote CCalc in 1999, but much of its code is a descendant of the E language compiler I wrote in 1985.