Check the EULA at https://www.tampermonkey.net/eula.php

Excerpt from point 4

> 4. NON-ALLOWABLE USES OF TAMPERMONKEY

> You are strictly prohibited from, and agree that you will not, adapt, edit, change, modify, transform, publish, republish, distribute, or redistribute Tampermonkey or any elements, portions, or parts thereof, including without limitation, to any elements, portions, or parts of Tampermonkey software (in any form or media) without the Company’s prior written consent. [...]