What are MAXScript Extensions?
Extensions are merely MAX plugins that specifically affect MAXScript. For instance, there are material plugins that add materials but there are extensions that add functions to MAXScript that were not previously available. Some extensions let you read binary files, some let you track the mouse over a mesh, another gives you control of a netrender – extensions fill small gaps in what MAXScript is allowed to do. Note that if you create a MAXScript that utilizes a extension, you will need any users of your script to also have the extension installed.