What you need to know:
- Always bubbling just beneath the surface, the on-again, off-again rivalry between Musk and Facebook creator Zuckerberg has boiled over with the launch of Twitter-clone Threads
- Blood feuds in the tech industry are not new, with Apple icon Steve Jobs and Microsoft's Steve Ballmer, for example, known to engage in battles that would leave those on the other side remembering them for years.
After years of bad press and scandal, Mark Zuckerberg is seeing his reputation spruced up in the fickle world of tech, largely thanks to the increasingly unpredictable behavior of Elon Musk.
Always bubbling just beneath the surface, the on-again, off-again rivalry between Musk and Facebook creator Zuckerberg has boiled over with the launch of Twitter-clone Threads.
Meta's new app has provoked the Tesla titan to sue Zuckerberg as well as unfurl a spate of potty-mouthed trolling on Twitter.
"It's definitely unique to see two people, who obviously are just ungodly wealthy, be in this kind of grudge match," said Andrew Selepak, assistant media professor at the University of Florida.
"But it does seem a little bit one-sided" with Musk clearly engaging in "childish behavior," he added.
Any blow-by-blow account requires wading into the often arcane back-and-forth that takes place on social media.
One altercation began on Threads when the official account of fast-food chain Wendy's made a friendly jibe at Musk's expense, which Zuckerberg tagged with a laughing emoji.
This quickly met the wrath of the mercurial Tesla boss: "Zuck is a Cuck," Musk wrote on Twitter, using a slur embraced by the far-right to slander Zuckerberg as a shill for the establishment.
Musk then proposed "a literal dick measuring contest."
'Learning is failing'
Zuckerberg has ignored the provocations, but hasn't always stayed above the fray.
Two weeks ago, before the release of Threads, he offered, maybe as a joke, to meet Musk for a bare-knuckled cage fight.
And in the hours after Threads was released, he went to Twitter for the first time in more than a decade to post a popular meme of Spider-Man pointing at another Spider-Man -- a tacit acknowledgment that, yes, he had copied Twitter.
Zuckerberg, who is 39, now cultivates a calmer image as big tech's muscle-toned wise man who practices martial arts and cares for his young daughters, all while delivering huge profits.
"Part of learning is failing," Zuckerberg recently told the Lex Fridman podcast.
"The moment that you decide that you're going to be too embarrassed to try something new, then you're not going to learn anything anymore," he added.
Fading are the memories of the Cambridge Analytica scandal and Zuckerberg being hauled in front of US lawmakers to defend his company's actions during the 2016 US election.
Even last year's failure to make something out of virtual reality, with billions of dollars written off and thousands of staff fired, has faded from the headlines.
But the Musk antics have helped more than anything to rehabilitate the Facebook founder.
"These attacks by Musk have done nothing but help Zuckerberg's image," said tech industry analyst Rob Enderle.
Evil 'I can understand'
Threads was pushed out last week to Instagram's 2.3 billion users (except in Europe), and more than 100 million have signed up.
Those praising Threads have often been those who expressed alarm over the years about Facebook and especially the company's close tracking of users and relentless harvesting of personal data.
Threads, which shows no ads yet, is no different, with users asked to give Meta permission to track them closely across the internet.
Those demands have delayed the app's launch in Europe where new legislation limits the ability of Meta to track and share data across its family of platforms.
But for analyst Carolina Milanesi, a close observer of the industry, "at least I can understand the evil that is profit-driven, versus Twitter, which is just an egotistic, rich man who has despicable, ethical bearings."
Blood feuds in the tech industry are not new, with Apple icon Steve Jobs and Microsoft's Steve Ballmer, for example, known to engage in battles that would leave those on the other side remembering them for years.
"Balmer threw furniture around when people were leaving for Google and there were certainly some interesting stories around the time of Netscape (in the late 1990s), but this is bonkers," said Enderle.