Histrix is a JavaScript calculator with the same functionalities that the classic calculator from Windows XP / Windows Vista.
Besides including all the buttons and features of both standard and scientific modes from the Windows calculator, it includes also a brief and very useful description of the functionality provided by each button.
Ideal for those who wants to use the classic calculator provided by Windows XP / Windows Vista.
There is also a version of this calculator for Google Chrome available at: https://chrome.google.com/webstore/detail/histrix-calculator/lgdfflejppjaglpjmkigldlpmkhfppcc