It is still in force, in most if not all EU mainland countries and Switserland. e.g. http://wetten.overheid.nl/BWBR0004825/HoofdstukII/5/Artikel1... for the Dutch equivalence.

It basically means on a level crossing that you should yield to the car that is to your right. This a basic rule, adapted in priority by signaling law enforcement, traffic lights, traffic signs, signs on the floor of the road, and then mutual understanding between all drivers. On a roundabout its the otherway round (priority is to the car on the left, by virtue of cars on the roundabout having priority). This will be reinforced by signs next to the road and special triangels on the road surface (e.g. see https://nl.wikipedia.org/wiki/Haaientanden_%28verkeer%29).

It is the fall back rule in case there are no signs or other regulations. i.e. in the us its is the fallback rule for a fourway stop situation. In the EU its the basics and people drive in the expectation that if you are on their left you will yield as in accordance with this rule.

It exists in Norway, there are two roadsigns for it, one is https://upload.wikimedia.org/wikipedia/commons/thumb/9/9f/No... and the "stop doing it now" is the same with a black line accross it.

Don't know about France, but Right-has-right-of-way is still valid in some countries. I know for sure we have it in Lithuania.

It's less and less used, because most new intersections have priority markings. But it still helps in parking lots and unmarked intersections.