How does this compare with GumTree? It’s weird that the page doesn’t even mention existing state-of-the-art tools for this task.
edit: I’ve compared GumTree and difftastic myself while working on a project this past week. Difftastic is harder to use programatically (the JSON format is unstable and leaves something to be desired) but other than that it’s miles and miles better.
The manual talks about some of the older alternatives that influenced it. Doesn’t directly compare them though https://difftastic.wilfred.me.uk/tree_diffing.html