CalcWorks for Mac

From John Brochu:

CalcWorks is not just another "me-too" calculator, like so many that have been released lately. It was originally released in 1994, and written up in several Mac publications of the time, awarded 5 mice by Macworld magazine, and an Honorable Mention in the 1994 MacUser Shareware Awards. CalcWorks was ultimately honored with a "Most Elegant Product" Award by Apple themselves in the 1997 Apple Human Interface Design Excellence Awards, the only non-commercial product to be so recognized.

CalcWorks is a professional, easy-to-use, fully customizable desktop calculator for your Macintosh, with comprehensive scientific and binary math functions, editable constants and conversions, printable paper tape, optional RPN, and a very realistic look and feel.

CalcWorks includes all the latest Apple color themes. The buttons, the display, and the background can be customized and even the buttons themselves can be rearranged to suit your taste (after registration).

CalcWorks SE includes all the same functions and features as CalcWorks except the binary math functions, and the interface has been simplified for novice users. Both versions are fully customizable (after registration) and a single registration allows you to use both versions.