I'm aware of several resources for searching the national or regional (e.g. EU) patent databases, but have found no tool for searching patents in all (or even several) countries at the same time.

Is there a resource for searching patents globally?

I'm aware of several resources for searching the national or regional (e.g. EU) patent databases, but have found no tool for searching patents in all (or even several) countries at the same time.

Is there a free resource for searching patents globally?