Opensource

I'm a tournament organizer for a local Smash tournament. We normally host our brackets on start.gg. However, the site is pretty unreliable. Occasionally, we've had to run the bracket on challonge.com instead. Recently, the venue wifi was having issues and we almost had to run it on our phones which wouldve been brutal. Every alternative I can find is either web-based or is commercial software for big E-sports events. I just need software on my laptop (I'm running Linux Mint, the other TO uses a MacBook) that can generate a double-elinination bracket based on a seeded list of entrants. After that, it should be able to track the bracket progress over the course of the event. This seems like a pretty simple concept but I haven't been able to find anything.