The Limbo song asks, “How low can you go?” Limbo is a strategy for scaling collaboration in software projects by reducing the volume of changes to be merged and increasing the velocity and reach of change propagation. post 
The original Limbo paper suggests that changes should be transformations of the Abstract Syntax Tree of the program. However, until the inevitable day when all changes are Tree Transformations, it is useful to experiment with textual diffs, just to see what Limbo will feel like, what incentives it creates.