Elon Musk took the stand Tuesday in a pivotal trial against Sam Altman, his former friend and co-founder of OpenAI. The lawsuit centers on OpenAI's pivot from its original non-profit mission, a move Musk alleges is "not OK to steal a charity."

Musk's legal team contends that Altman, Greg Brockman, and Microsoft usurped control of a charity dedicated to safe, open AI development. Musk is seeking damages and Altman's removal from the board. The trial, unfolding at the US District Court in Oakland, is expected to last several weeks.

As the first witness, Musk detailed his extensive career, emphasizing his demanding work ethic of 80-100 hours weekly without vacations. He expressed concerns about AI surpassing human intelligence as soon as next year, likening the challenge to controlling a vastly intelligent, independent child.

Musk recounted OpenAI's founding in 2015, driven by a desire to counter the profit-driven AI efforts of tech giants like Google and Facebook. He stated that while open to a for-profit arm, profit limits were intended, and the venture should cease once Artificial General Intelligence (AGI) was achieved.

OpenAI counters that Musk's claims stem from disappointment after he failed to gain majority control. Their legal team asserts Musk attempted to commandeer OpenAI and merge it with Tesla, and that his primary motive was winning the AI race, not preserving non-profit status. OpenAI highlights that Musk left its board in 2018 after disagreements.

The trial is set to feature testimony from Altman and Microsoft CEO Satya Nadella.