Editors
Booster's Lab
by Noxid
An actively updated in-development editor geared towards cross-platform and cross-engine modding.Booster's Lab v0.2.5.1
Cave Editor
by Wistil
Has a number of features not present in Booster's Lab. Both editors are compatible with each other so it's down to personal preference as to which interface you prefer.Cave Editor v0.99d
Source Code