What can I do with this being open source if I cant use it for a competing service? Run an inhouse instance?

Yep. And that's great!

Yes, personal/in-house use.

It's crazy to think people actually lived through this.

Even crazier that a number of people were a victim of the bomb on Hiroshima, and a few days later also got hit by the bomb on Nagasaki.

And some of them even lived through that.

https://vdo.ninja/ is pretty good but not sure if OSS.

Have you seen https://serlo.org/ ? You should join forces

No. Thank you. Will reach out to them.