You're asking for software, all software requests go there.
You're asking for authoring software for bluray (not really video editing - but...) .
And I'd probably suggest starburn - not open source, but free.
Depending on the tool, either it'll automatically upscale the media to HD.
> Is there a program I can buy that can make low quality video into bluray so it would look good on a giant movie screen? Also, we are sensitive to copyright infringement but this will not be a public event. Only like 10 of us at the most closed to the public.
There is no magic tool that will make it look better though. It'll just blow it up.
If you put a regular DVD in the player (yes, BR plays standard DVDs) it'll upcale as well.
But specifically:
> Is there a program I can buy that can make low quality video into bluray so it would look good on a giant movie screen?
No. It's just going to spread out 1 pixel to four. That's what upscaling is.
Getting the films in HD is the only way to get it to look better.