"easiest/low tech" would be some sort of unix file-locking and inode. Only works if you are on the same host machine though...AAAND sounds like it would be quite hacky.

Which is a good thing :) I am all in for asking questions. If someone can't answer them, it usually means they have not thought about it and are either ignorant or will learn something themselves :D

(like me for your question, as I never tried TabSub with internet disconnected. Was delighted to see it works nevertheless)

Will check this tomorrow. If you come to it in the meantime, feel free to open a PR :) Thx

Works for offline apps as well :) (you would need to download the tabsub JS ofc and not use it from my server)

It means, that you don't need an internet connection for this to work :) (so it is no rabbitmq or so which runs on a server and the browser is just the client)

You can try on the demopage when you

1. play the songs each (for them to buffer a little audio snippet)

2. open the page in a second tab

3. Disconnect from the internt

Still works :D