New York CNN Business  — 

Tesla (TSLA) CEO Elon Musk doesn’t seem to approve of Microsoft’s deal with OpenAI — the research company he co-founded in 2015.

The Tesla and Space X founder criticized Microsoft (MSFT) in a tweet following news that the company acquired an exclusive license for GPT-3, a language model created by OpenAI, that generates human-like text.

“This does seem like the opposite of open. OpenAI is essentially captured by Microsoft,” Musk tweeted on Thursday.

OpenAI, which was initially launched as a non-profit research company, was co-founded by Musk and included a heavy-hitting list of donors including Peter Thiel and Microsoft. The company’s goal is “to advance digital intelligence in the way that is most likely to benefit humanity as a whole, unconstrained by a need to generate financial return.”

Microsoft’s Executive Vice President and Chief Technology Officer Kevin Scott announced the move in a blog post Tuesday, saying it will allow the company to “leverage its technical innovations to develop and deliver advanced AI solutions for our customers,” and “create new solutions that harness the amazing power of advanced natural language generation.”

Scott noted in the company’s blog post that GPT-3 would still be accessible via OpenAI’s application programming interface platform (API).

But Musk isn’t buying it and neither are other Twitter users, who feel the collaboration contradicts OpenAI’s aim of making its work accessible to all.

In February 2018, Musk stepped down as chairman of the company to “eliminate a potential future conflict” due to Tesla’s boosted efforts in AI development.

It’s unclear how much exclusivity OpenAI’s licensing deal will grant Microsoft with GPT-3.

AI’s battle of the billionaires

Despite Musk’s own investments in artificial intelligence, the billionaire has also been one of its most vocal critics.

Musk called AI an “existential threat” to humanity in 2017 and has also participated in a few billionaire feuds on the topic over the years. He notably called Facebook CEO Mark Zuckerberg’s understanding of AI “limited.”

He’s also feuded with Microsoft founder Bill Gates. Gates holds an opposing view to Musk — who has made warnings of a future when he says the global race for AI technology will result in World War III.

“The so-called control problem that Elon is worried about isn’t something that people should feel is imminent,” Gates said in a joint interview with Microsoft CEO Satya Nadella for the WSJ. Magazine. “This is a case where Elon and I disagree. We shouldn’t panic about it. Nor should we blithely ignore the fact that eventually that problem could emerge.