World2Xplane – tool to convert osm data, including 3D objects
OSM2XP – Converts OpenStreetMap data into X-Plane scenery packs (no longer available, outdated)
OverlayEditor – For creating and editing X-Plane Sceneries. If OpenSceneryX is installed, this allows you to create scenery packs that use it. This is a great, easy to use editor, helping to place objects using background images.
WorldEditor (WED) – For creating and editing X-Plane Sceneries .dsf and also for apt.dat. This is the official scenery building tool, developed and supported by Laminar.
G2XPL – A program and also a plugin for loading textures onto X-Plane default scenery.
SimTiles – SimTiles creates night textures and winter textures for x-plane from photoreal sceneries.
Ortho4XP – Generates photo sceneries from many services, transitions at coasts and inland water, overlay files, written in Python, this is more for experts.