It was not that long ago that Sam Altman’s OpenAI appeared to be enjoying a comfortable lead in the corporate race to bring artificial intelligence to the masses.

OpenAI created the fastest-growing consumer app in tech history, held more than $100 billion in the bank and teamed up with the world’s most powerful computing giants. But companies are always rising and falling in Silicon Valley.

In just a few months, Anthropic, OpenAI’s smaller rival, has added thousands of big businesses as customers. It has more than doubled the revenue it expects this year to $19 billion, up from $9 billion last year. And its technology is being trumpeted in some tech circles as the best among its peers.

Even an ugly fallout with the Pentagon over a contract has helped Anthropic — at least in the court of public opinion. Anthropic’s smartphone app soared to the No. 1 spot in Apple’s App Store downloads after OpenAI jumped in with its own Pentagon deal.

The contract controversy involving the US defence department, OpenAI and Anthropic was the latest round in a long-running and deeply personal feud between the tech industry’s two most important AI start-ups and two executives with differing views of how AI should be created.

Other companies, like Google, Microsoft, Meta and a wide range of start-ups around the world, are also vying for AI leadership. But OpenAI and Anthropic, opposing camps with headquarters roughly 2 miles apart in San Francisco, have become the standard-bearers for tech’s AI frenzy.

Anthropic’s CEO, Dario Amodei, was vice-president of research at OpenAI, but he thought Altman was moving too quickly to commercialise the technology. He quit and took a group of OpenAI researchers with him to create Anthropic as a type of for-profit company that vows to meet certain standards for social impact and accountability.

Amodei’s and Altman’s beliefs on how AI should be developed have had direct implications on the companies’ businesses. Altman has pushed his company to move fast, while Amodei has urged caution because of his concerns over safety and his workers appear to back his cause.

Last summer, when the rivals began throwing around offers up to $500 million to attract Anthropic employees, most of them said no.

New York Times News Service