Now that Wade has XSquawkBox 1.0.3 out, I've been thinking about CSLs - that is, the collections of simplified airplanes that XSquawkBox uses to draw the other users. The CSL system was invented back in the days of X-Plane 6, and it's getting a bit long in the tooth. You can't use OBJ8 files, and it doesn't understand a lot of the modern rendering tricks that authors use with the standard tool chain.
Plane-Maker has advanced quite a bit since then too - to make the original CSL, I had to create a special one-off hacked build of Plane-Maker to export aircraft as OBJs. This capability is now built into Plane-Maker, works a lot better, and even supports animation.
X-Plane now exports a native OBJ drawing interface to plugins. Besides giving plugins access to the fully optimized native OBJ draw code, this also means that plugins can draw objects with per-pixel lighting.
One more piece of the puzzle: in France Austin announced that we were working on a new ATC engine. One goal of this new engine is to provide ATC to the AI planes, as well as your plane, so that the other aircraft interact seamlessly in one simulated environment. (In X-Plane 9, ATC only directs you, and the AI are rogue planes that try not to buzz you when you're on the runway.)
This makes me wonder: should there be a next-gen CSL format that is shared between X-Plane and third parties, based on X-Plane doing the rendering work?