Just a thought on the Sandcastle... It would be helpful to have a tab that sorts all the demo galleries in the Sandcastle by date added.
There have been several demos added recently (3D Tile Clipping Planes, 3D Tiles Interactivity) that would be better emphasized if there was a way to present the gallery by date added. Context of newest Cesium functionality could also be inferred when seeing the demos chronologically.
Thanks for all the continued great work going into 2018, team Cesium! Clipping Planes will be great for refining floor-level perspective on a 3D building.