What is open source scripting language?

Answer 1

An open-source language refers to a programming language that falls within the parameters of open-source protocol. This basically means that the language is not proprietary, and with certain provisions (depending on the open source license), can be modified or built upon in a manner that is open to the public

Answer 2

Open-source software is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose.

The same applies to programming languages

(And also you can find its source code, that's why it's called open SOURCE)