Thankfully, this was done back in 2001, with the movie Revolution OS, which focuses on the "rise" of Linux. Granted, it's a one-side, no-frills documentary (meaning that at times, it can be a bit painful to watch), but as a basic introduction to open source and free software....it's rather entertaining. (Had I seen this before converting a Panasonic Toughbook into an Ubuntu-driven computing machine, I might have converted all of my computers over).
And thankfully, it's on You Tube....and I've embedded it for your viewing pleasure. Enjoy!