There are other patents for their implementation, and all are filed in multiple countries. Look at the blue sidebar under "Worldwide applications".

The linked one is just for the US version of a singular patent. It had applications in 14 other countries and WIPO, 6 of which are still active (plus US).

There are 195 (ish?) countries, not all of them nearly as litigious.

Any seller of software would be liable for selling software to US customers without a patent license.

I'm curious about the legal consequences of freely distributed software (e.g. open source). I wonder if the author/provider could be held liable if they: - knowingly (passively) or actively market to US customers (e.g. provide support) - are aware that US users are using it, and take no actions to prevent its distribution etc.

Can someone share their knowledge on this?

If European software incidentally infringes a US patent, and it is distributed freely, is the provider then liable? E.g. is Github basically liable for restricting US users from access to (distributing) patent infringing software?

As I understand, you can violate a patent just by importing something infringing. Selling it isn't necessarily a requirement for infringement.

https://blog.shp.law/index.php/2021/03/28/open-source-softwa...

I'm sure there's tons of patent violations in FOSS, but patents are usually just used to go after companies with big pockets.

Due to software patents (generally) not being a thing outside the US, or because it was demonstrated before patent application?