Structural Diffs

Tree Diffs

Most tree diff implementations focus on XML, and there's a great overview of techniques in this blog post.

Jane Street's patdiff implements a tree diff, using an A* algorithm.

JSON diff

json-diff provides a proper structural diff for JSON files.

graphtage

graphtage compares structured data by parsing into a generic file format, then displaying a diff. It finds the optimal edit sequence, and even allows things like diffing JSON against YAML.

Lisp diffs

sdiff and diff-sexp explore s-expression oriented diffs.

Autochrome is a structural diff for Clojure, using Dijkstra pathfinding. It does not track moves.