Also: European Union Aviation Safety Agency
EASA is based in Cologne. It develops the technical rules under which aircraft are certified, maintained and operated, and oversees how national authorities apply them.
Besides the EU member states, countries such as Switzerland, Norway, Iceland and Liechtenstein also apply EASA rules. For travellers in the German-speaking region, this means largely uniform standards.
For private jet clients, the key point is that commercial operators need an AOC under these rules and must comply with European flight and duty time limits for their crews.