In the ongoing feud between Elon Musk and seemingly every other player in the AI realm, but specifically OpenAI, his company xAI has now filed an antitrust lawsuit against Apple and OpenAI.

The suit, filed Monday in federal court in Texas, arises after public comments Musk has made (via tweet) about his frustration that his Grok AI app hasn't been higher ranked than ChatGPT in the Apple App Store. In the suit, per Reuters, Musk's attorneys claim that Apple and OpenAI have "locked up markets to maintain their monopolies and prevent innovators like X and xAI from competing."

And, the suit contends that a deal between OpenAI and Apple — which Musk cried foul over when it was inked last year — further muddies the competitive waters.

"In a desperate bid to protect its smartphone monopoly, Apple has joined forces with the company that most benefits from inhibiting competition and innovation in AI: OpenAI, a monopolist in the market for generative AI chatbots," the suit reads, per CNBC.

"If not for its exclusive deal with OpenAI, Apple would have no reason to refrain from more prominently featuring the X app and the Grok app in its App Store," the suit says.

An OpenAI spokesperson responded to the suit, telling CNBC, "This latest filing is consistent with Mr. Musk’s ongoing pattern of harassment."

Apple issued a statement saying that its App Store was "fair and free of bias" in how it displayed thousands of apps for download.

Musk has been in a protracted battle with OpenAI and its CEO Sam Altman, with legal filings getting volleyed back and forth over the last year or so. Musk has been in the process of suing OpenAI over what he says was an illegal move to abandon its original nonprofit mission. And he also made what Altman and others have called a frivolous offer in February to buy OpenAI for $97.4 billion. (Reuters just reported that, according to a court filing, Musk tried to enlist rival Mark Zuckerberg to help finance that purchase.)

OpenAI, meanwhile, filed the beginnings of a defamation suit against Musk in April, claiming that online comments and his arguably bogus offer to buy the company have harmed OpenAI. The legal filing suggested that Musk had engaged in a "years-long harassment campaign" and used "bad-faith tactics in an attempt to slow down OpenAI for his personal benefit."

The filing also argued that this was all about sour grapes for Musk, who had walked away from OpenAI after helping to found it. "Musk could not tolerate seeing such success for an enterprise he had abandoned and declared doomed," the suit says.

Earlier this month, a federal judge rejected Musk's attempt to get that suit dismissed.

Weeks ago, after Musk threatened his latest lawsuit involving Apple, Altman took a shot at him via tweet saying, "This is a remarkable claim given what I have heard alleged that Elon does to manipulate X to benefit himself and his own companies and harm his competitors and people he doesn’t like."

Altman is referring to the algorithm underpinning X, which we all know likely prioritizes tweets from Musk himself and forces many users to read them. The app already de-prioritizes tweets with links in them. And earlier this year, when Musk was trying to get in tight with Trump, he announced an "algorithm tweak" that would de-prioritize "negativity" in general — which critics said seemed convenient given that it highly prioritized negativity during Biden's term.

While xAI's latest Grok model reportedly scored higher on several cognitive tests than other AI models, its popularity among users has lagged — which may be reflected in Musk's lawsuit. Grok had 18.8 million monthly active users as of June according to one estimate, while ChatGPT is reportedly seeing 800 million or more weekly active users, and 2.5 billion prompts per day from users. The company expect to have 1 billion weekly active users by the end of the year.

Previously: Elon Musk Flips Out Over Apple's Deal With OpenAI, Threatens to Ban All Apple Devices