Oppenheimer may be one of the biggest box office events of the year and the IMAX version appears massively popular, with some theaters already sold out for the next few weeks. The IMAX version may also be on the biggest physical film reels ever produced. According to Cinemark, the 70mm print of the film is 11 miles long and 600 pounds. To get this movie ready for theaters, IMAX used technology that’s run by an iPad emulating a 20 year old piece of hardware—a PalmPilot.
https://www.vice.com/en/article/88x5gb/imax-still-runs-on-palmpilot-operating-system