xCalc is a simple calculator for Autodesk 3ds Max, created by markulie and written entirely in MAXScript. It provides basic calculation inside the application and includes a history feature. The project is hosted on the developer's GitHub repository, where the script file and README can be found.
Installation is done by drag and drop: the MaxScript file, markulie-xCalc-v0.3.ms, is dragged into a 3ds Max viewport to load the calculator. No additional dependencies are noted for the script version.
The available release is version 0.3, last updated on 28 October 2022, and this catalog lists xCalc as free. It is part of the scriptspot library of 3ds Max scripts. For the file, licensing terms and any later revisions, the developer's GitHub page is the place to check.