Rather than two giant 440px high images consisting of tiny text in the readme I'd quite love to read exactly what it does and why. Does it prune files in modules that are not needed? If so what heuristics does it use to prune files? Or does it prune modules that are not needed?

Reading the code[1] it appears to delete directories and extensions based on a blacklist.

1. https://github.com/tj/node-prune/blob/master/prune.go#L15-L5...