Silicon Valley moguls are weighing in on Elon Musk's battle with OpenAI, and it's getting cattier than a 'Real Housewives' reunion

• Other major investors are weighing in on Musk's lawsuit against OpenAI.
• Vinod Khosla, an early OpenAI backer, said Musk's lawsuit "feels like a bit of sour grapes."
• "Vinod is lobbying to ban open source," the venture capitalist Marc Andreessen said of Khosla.

Elon Musk and his fellow billionaire tech bros are brawling over their differing views on OpenAI, and the back-and-forth is getting ugly.

On Thursday, Elon Musk sued OpenAI and its CEO, Sam Altman. The billionaire accused OpenAI of violating its nonprofit mission when it partnered with Microsoft. Musk, who cofounded OpenAI alongside Altman, left the company's board in 2018.

The move by Musk to sue OpenAI didn't go down well with the company's backer Vinod Khosla. Understandably, seeing as in 2019, Khosla's venture-capital firm invested $50 million in OpenAI.

"With @elonmusk, feels like a bit of sour grapes in suing @OpenAI, not getting in early enough, not staying committed and now a rival effort," Khosla wrote in an X post on Saturday, referencing Musk's artificial-intelligence company, xAI.

"Like they say if you can't innovate, litigate and that's what we have here. Elon of old would be building with us to hit the same goal," Khosla continued.

"Vinod doesn't know what he is talking about here," Musk wrote in a reply on X.

The venture capitalist and Netscape cofounder Marc Andreessen took shots at Khosla as well. In an earlier post, Khosla had defended OpenAI and its leadership, saying they "have pushed out better products faster than anyone in AI."

"Vinod is lobbying to ban open source," Andreessen wrote on X.

Thursday's lawsuit appears to be a culmination of Musk's various grievances against OpenAI. Since leaving OpenAI's board, Musk has been critical of Altman's leadership of the company.

Altman appears to have limited his response to the Musk lawsuit to a couple of cryptic tweets. His chief strategy officer, Jason Kwon, went a little further.

"We believe the claims in this suit may stem from Elon's regrets about not being involved with the company today," Kwon wrote in an internal memo on Friday, according to CNBC.

In 2019, Musk talked more about his decision to leave the board. Besides needing to focus on Tesla and SpaceX's engineering and manufacturing problems, he said, he "didn't agree with some of what OpenAI team wanted to do."

Musk didn't elaborate on what those disagreements were.

Then, in February 2023, Musk said the development of OpenAI was "not what I intended at all."

"OpenAI was created as an open source (which is why I named it 'Open' AI), non-profit company to serve as a counterweight to Google, but now it has become a closed source, maximum-profit company effectively controlled by Microsoft," Musk wrote on X.

Representatives for Musk, Khosla, and Andreessen didn't immediately respond to requests for comment from Business Insider sent outside regular business hours.