One very important point about driving in France, Germany, Austria etc is the issue of winter tyres as well as snow chains. NewNew mentioned above that they are compulsory in Germany - the situation is a bit more complex than that. They're not actually compulsory throughout winter, only when the road conditions demand it, ie for snow, slush and ice. So if the road is absolutely clear you're not obliged to use them. In fact, although everyone calls them Winterreifen, the official name is S+M Reifen (stop sniggering at the back) für Schnee und Matsch. BUT, in practice just about everyone in Central Europe will have winter tyres or all-weather tyres on throughout winter (we get ours changed over every April and October), and they make a huge difference in the grip it gives the road.
What this means is that if you're driving along up in the Alps, you might be deciding not to put your snow chains on because nobody else has them on yet, but in fact they can wait longer before the snow chains are needed because they have better grip using winter tyres, IYSWIM. So you might be lulled into an unwarranted security. With summer tyres you absolutely have to put the snow chains on the moment you get to a snow-covered road (don't you? - surely you'd have no traction otherwise).
When we went skiing in the Czech Republic last year it was notable that virtually nobody was using chains to get around the mountain villages on a thick layer of compacted snow; the winter tyres were enough to deal with that. Same applies to our little side street here in Central Europe; we get snow every year, and the main road is kept completely clear of snow, but our little side street is uncleared and it would be impassable on summer tyres.
We didn't use our snow chains last year because of the winter tyres, but we also had a pile of grit in the boot and a shovel just in case we got stuck at any point and needed extra traction. Wasn't needed in the end.