What Does Open-Source Language Mean?

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.

Techopedia Explains Open-Source Language

Programming languages were developed following the invention of the first digital computers in the mid-twentieth century. As they evolved and diversified, many in the computer and software development communities began to see a potential for non-proprietary software and coding languages.