Any open source software should be considered "international" and there are a lot of European contributions to that universe.

The topic of "European" programming languages is highly interesting in the sense that there were a lot of highly developments done in Europe, but they are often less noticed than the counterparts popular in the US. The reason to look more into them would not be so much today's independence, but more to resurrect good concepts that kind of got ignored by history.

There is the ISLisp standard, of course the treasure chest of languages and works boy Nikolas Wirth and so much more. Europe has many great universities, their creations usually are free.

Of course, you could call Python an European language and Go heavily draws from the Wirth's language family.

Still in it's infancy but Moose OS is fully EU built github.com/onmoose/os

Ideally those are free and open source