PBW games - so many SEIV versions!

[Artaud]

I'm thinking of punging into the PBW universe, but I've noticed that among the games where players are needed there are many versions of SEIV being played.

My question: is SEIV Deluxe version 1.94 compatible with SEIV Deluxe version 1.95 (what I have)? I've also noticed several SEIV version 1.91 games going. I don't suppose any of those would be compatible with Deluxe...

I've noticed a couple of Devnull games going, but none for the version of Devnull I have, which is Devnull Gold. I'm not even sure Devnull Gold is the latest version.

I noticed at least one Dark Nova game, but not for the latest version, which AFAIK is DN4.23.