The bitter legal fight between Elon Musk and the leading artificial intelligence firm, OpenAI, led by Sam Altman, may come down to a few pages in one executive's personal diary.

Over the next month or so, a who’s who of the technology industry is expected to appear in the Ronald V. Dellums U.S. Courthouse in Oakland, Calif., for a legal showdown between Elon Musk and the arti...

Legal discovery in the case has already unearthed titillating details involving a wide cast of characters, including Shivon Zilis, a former OpenAI board member and the mother of several of Musk’s chil...