u/Vandoid

This small module does one thing: it keeps PCs, journals, and macros synchronized across different worlds on your server.

• Why would you want this? Maybe you want to share the same characters across a bunch of one-shots. Or maybe you want to split your campaign across several worlds (so you don’t have to keep pushing old scenes, NPCs, etc. into compendiums to keep your world from getting sluggish)…and have the player’s journals follow them. Or maybe you rotate DMs and want each to have their own world. Or maybe isolate the party’s bastion/home base in its own world where you can give the players elevated privileges.
• What if you don’t run your games that way? Then you don’t need this. But it was something I wanted for my own games, and I’m sharing it in case there’s others who would find it useful.
• Does it work across servers? No. Omnipresence uses compendium packs to share resources across worlds. These compendiums live on your server, and therefore sharing is limited to worlds on your server.
• How are permissions handled? Ownership of actors, journals, and macros are keyed to the user name. This is because Foundry has no underlying user ID to tie users together across worlds. So it's up to you to ensure that players keep their user names across worlds. Maybe if Foundry ever implements OIDC we can do something more foolproof.
• Can't I just do this synchronization manually? Sure. It's just complicated and tedious. That's why I wrote the module.
• Is this your first module? Yes it is, though I’ve done software development for several decades. I continue trying to improve it; at the time of writing this post, I’ve published 16 releases of the module.
• Why this list of game systems? The module uses compendiums to share actors, and actor compendiums are tied to specific game systems. I picked the six most popular; if you want support of another game system, just let me know and I’ll add a compendium for that.
• How was AI used for this module? No AI was used for creative content; that’s for humans. I used AI coding tools to write the code and test it, paired with manual code review and testing. 
• Is this free/open source? Yes, via the MIT license. Source can be found here: https://github.com/bularzik/Omnipresence
• How do I install it? This module has been published on Foundry’s server, so you can install it just like you install any other module: go to the Add-on Modules tab, select Install Module, and search for Omnipresence.