Grunt

Grunt: The JavaScript Task Runner. Using Node.js.

Free Open Source Mac OS X Windows Linux Node.JS

Soulver

Soulver helps you do quick calculations and work things out. Use Soulver to play around with numbers, do "back of the envelope" calculations, and solve day-to-day problems.

Commercial Mac OS X

Numeric Notes

Numeric Notes – is not just a totally new way to count, but also possibility to keep and share calculations on your Mac. Individual notes for home calculations, work and shopping.

Commercial Mac OS X

Console Calculator

Console Calculator is a powerful calculator with a simple console interface. This calculator supports many built-in mathematical functions, remembers recent entries, supports creation of user defined variables and custom functions.

Commercial Mac OS X Windows