Hi! We're open to everyone, you're very welcome to be here ( ･∀･)っ凵凵c(･∀･ )
Having every game submission also be open source would be amazing but it's ok to keep it "closed", as we mainly want to promote the use of any open source in games development.
The fact you use several open source programs in general is amazing and promotes the use of open source software in a wide variety of ways!
The voting works the same as other ranked game jams, you'll be able to vote on a few different things like how enjoyable you found a game submission, and after the voting period ends it'll display how every game ranked depending on how people voted on each category 乁( ˙ω˙ 乁) it's solely for a bit of fun and shouldn't be taken too seriously.