open-source

American  

[oh-puhn-sawrs, -sohrs] / ˈoʊ pənˈsɔrs, -ˈsoʊrs /

adjective

1. Computers. pertaining to or denoting software whose source code is available free of charge to the public to use, copy, modify, sublicense, or distribute.

2. pertaining to or denoting a product or system whose origins, formula, design, etc., are freely accessible to the public.

---

open source British  

noun

1. 1. intellectual property, esp computer source code, that is made freely available to the general public by its creators

   2. ( as modifier ) Compare closed source

      open source software

---

open-source Scientific  

1. Relating to source code that is available to the public without charge. Open-source code is often enhanced, improved, and adapted for specific purposes by interested programmers, with the revised versions of the code are made available to the public. For example, most of the code in the Linux operating system is open-source.

---

Etymology

Origin of open-source

First recorded in 1960–65

Example Sentences

Muse Spark is the first in a new series of models, succeeding Meta’s previous open-source efforts with its Llama series.

From MarketWatch • Apr. 17, 2026

The current White House has been supportive, putting forth an AI Action Plan that encourages open-source development.

From The Wall Street Journal • Apr. 17, 2026

The U.S. government should demonstrate it is invested in the success of open-source AI development.

From The Wall Street Journal • Apr. 17, 2026

In January, Alibaba’s Qwen family surpassed 700 million downloads to become the most widely adopted open-source AI system on the planet.

From The Wall Street Journal • Apr. 17, 2026

At the moment, he had NT 5, NT 4, Work Station, Windows 98, and he and Eric had begun fooling around with Linux, the complex, open-source software system rapidly spreading across the world.

From "Geeks: How Two Lost Boys Rode the Internet Out of Idaho" by Jon Katz