August 25, 2025 xAI has announced that they are issuing and Open-Source version of Grok 2.5 — a move likely intended to mirror or challenge OpenAI’s earlier launch of an Open-Source version of ChatGPT 3.0. But as always, the story is not quite that straightforward, as industry watchers are pointing out.

Elon Musk, who co-founded OpenAI but parted ways in 2018, has repeatedly accused OpenAI of straying from its original mission. At the Qatar Economic Forum in May 2025, he lambasted OpenAI for shifting to a “for‑profit company that is closed source,” calling it a betrayal of its original non‑profit, open‑source ideals .

That criticism seems ironic or at least, hollow now: Grok 2.5’s “Open-Source” version is released under the Grok 2 Community License Agreement, which is revocable, grants only limited (primarily non‑commercial or tightly controlled commercial) use, requires “Powered by xAI” attribution, forbids using outputs to train competing models, and limits trademark usage. In short, it does not conform with any definition of “Open-Source.” Tech observers have called it “open weights” rather than “open source” and criticized the license’s restrictiveness.

By contrast, OpenAI’s earlier releases under the Apache 2.0 license represent classic open‑source credentials: irrevocable, permitting reuse, modification, fine‑tuning, commercial use, and broadly recognized by the Open Source Initiative .

The irony is clear: Musk’s criticism of OpenAI’s lack of openness carries weight — but Grok 2.5’s licensing paints a more constrained picture.

Looking beyond that centerpiece, other models fall across a permissiveness spectrum:

• Meta’s Llama 3 introduces mandatory “Built with Meta Llama 3” branding, deployment caps beyond 700 million users, and excludes certain EU users in some cases — not to mention restrictions on competing use and trademark controls.
• At the open end is DeepSeek, released under MIT and OpenRAIL-style licenses, offering developers some of the broadest freedom for commercial and innovation purposes.

So, Musk’s claim to have an Open-Source version of Grok 2.5 is slightly exaggerated. Despite his past criticism of OpenAI, they seem to have provided a truly Open-Source version of their AI model, rivalled only by DeepSeek. Grok is closer to Meta’s Llama and might be more appropriately labelled as “source-available” with signficant caveats and restrictions.

And this is a good warning to developers and others who are hoping to build solutions on what they think is Open-Source code. When an AI model is labeled “open source,” take a breath — and open the license. The term is often used loosely. Grok may come with open-source branding, but the real answer to “how open is it really?” lies in reading the fine print.