FSX/P3D. In my personal opinion (and I am not sure how this would work) but I think all freeware scenery developers that are known for high quality should release through Orbx. Those object and flow libraries can really make the difference in any scenery. Orbx developer Thomas Zipfel has returned with his second German freeware destination Rügen Güttin on island of Rügen in the Baltic Sea. Have a look at his latest work. Nicht schlecht!