It's been an eventful weekend at OpenAI's headquarters in San Francisco. In a surprise move Friday, the company's board of directors fired co-founder and CEO Sam Altman, which set off an institutional crisis that has seen senior staff resign in protest with nearly 700 rank-and-file employees threatening to do the same. Now the board is facing calls for its own resignation, even after Microsoft had already swooped in to hire Altman's cohort away for its own AI projects. Here's everything you need to know about the situation to hold your own at Thanksgiving on Thursday. This saga began forever ago by internet standards, or last Thursday in the common parlance.

Almost the entire staff of OpenAI has now signed a letter threatening to leave and join a new venture led by ousted CEO, Sam Altman. Some 738 out of its around 770 employees, about 95 percent of the company, are now listed on the letter released early this morning. The letter calls for Altman and his fellow OpenAI cofounder and close associate Greg Brockman to be reinstated, for the board that fired Altman and removed Brockman from his position as chair to resign, and for new board members to be appointed. Altman was fired from his position as CEO of OpenAI on Friday. Brockman was removed from his position as chair and quit the company hours later in protest over Altman's removal.

The ascension of an insider CEO can be a bit underwhelming. When Satya Nadella took the helm of Microsoft in 2014, some employees and investors were disappointed. The search committee had spent months sifting through more than 100 potential leaders, looking for someone who could revive the spirit of innovation that had once defined the company. Along the way, some Wall Street analysts interpreted the fact that no clear external candidate was emerging to indicate that "Microsoft couldn't attract an appealing CEO after years of dwindling relevance," the Wall Street Journal reported. And then, on a frigid January day, they got a 22-year Microsoft veteran as CEO.

Stepping into such a significant role can't be easy, but Shear appears to have a sense of early priorities. In his announcement post on X early Monday, he outlined three areas of focus for his first 30 days on the job: He said he intends to investigate "the entire process" that brought the company to this point, open lines of communication to partners and OpenAI employees and rebuild the management and leadership teams "in light of recent departures."

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"If many OpenAI employees choose to migrate to Microsoft to join Mr. Altman and Mr. Brockman, then not only would Microsoft hold a license to OpenAI's (intellectual property) up to (artificial general intelligence, an AI-system that's generally smarter than humans), but Microsoft would also be effectively acquiring OpenAI's core differentiation -- its ambitious and experienced technical talent," Havemeyer added.

OpenAI is on its third CEO in three days, after appointing Emmett Shear as interim CEO, less than 72 hours after its board ousted former CEO Sam Altman in a shock move on Friday Nov. 17, claiming he had not been "consistently candid in his communications with the board." The company said on Friday it was replacing Altman with chief technology officer Mira Murati but over the weekend, multiple publications reported that Altman was in talks with the OpenAI board to return as CEO. After the departures of Altman and chairman and president Greg Brockman, who resigned, the board comprises chief scientist Ilya Sutskever and three independent directors: Quora CEO Adam D'Angelo, tech entrepreneur Tasha McCauley, and Helen Toner of D.C.-based think tank the Center for Security and Emerging Technology. Bloomberg reported that Murati was negotiating for Altman and Brockman to return to OpenAI, and that Microsoft boss Satya Nadella was playing a central role in the talks. The negotiations ultimately came to nothing, and on Sunday evening Pacific time, reports emerged that OpenAI was appointing Shear as CEO.

The firing of Sam Altman as chief executive of OpenAI on Friday took the tech world by surprise and has triggered a Silicon Valley corporate drama. Altman is not just the CEO of the company behind the ChatGPT artificial intelligence chatbot. He is also the figurehead of a revolution in AI that has enthralled the public and investors but also alarmed industry insiders and experts. Here we answer some key questions about what's been going on and why it matters. OpenAI is the San Francisco-based company behind ChatGPT, a chatbot that has wowed users with its ability to produce highly convincing text responses to human prompts – from writing academic essays to creating recipes and summarising lengthy documents.

Hundreds of staff at leading artificial intelligence company OpenAI have threatened to quit and join Microsoft after the sudden firing of the company's co-founder Sam Altman. The OpenAI staff said they would follow Altman, who said he would be starting an artificial intelligence (AI) subsidiary at Microsoft after his surprise removal from the company that created the ChatGPT chatbot, which led to the rapid rise in AI tech. In a letter, some of OpenAI's most senior staff members threatened to leave the company if the board was not replaced. "The process through which you terminated Sam Altman and removed [co-founder and former president] Greg Brockman from the board has jeopardized all of this work and undermined our mission and company," the letter, first released to the technology news outlet Wired, reads. "Your conduct has made it clear you did not have the competence to oversee OpenAI". "Microsoft has assured us that there are positions for all OpenAI employees at this new subsidiary should we choose to join."

If you were offline this weekend, my colleague Will Douglas Heaven and I break down what you missed and what's next for the AI industry. Friday afternoon Sam Altman was summoned to a Google Meet meeting, where chief scientific officer Ilya Sutskever announced that OpenAI's board had decided Altman had been "not consistently candid in his communications" with them, and he was fired. OpenAI president and cofounder Greg Brockman and a string of senior researchers quit soon after, and CTO Mira Murati became the interim CEO. Saturday Murati made attempts to hire Altman and Brockman back, while the board was simultaneously looking for its own successor to Altman. Altman and OpenAI staffers pressured the board to quit and demanded that Altman be reinstated, giving the board a deadline, which was not met.