Snapdrop if they both have a gui/webbrowser. https://github.com/SnapDrop/snapdrop

Scp otherwise

No. It’s a weekend job that implements only the tiny subset of features I care about.

Nextcloud Talk

It’s great. Been using it for years. Even wrote my own bridge that integrates beautifully with their first party ones.

Yup. It does individual/group chat messages too.

Correct!

Finished setting up an email server and am now looking into a matrix nextcloud bridge. Doesn’t seem to exist, so I guess I’m writing one.