A quick and dirty approach to make git-diff on MS Office documents use the decompressed XML instead of treating them as binary. Known bugs: Complains on empty components (notably including the always-present [Content_Types].xml), and actually shows all changes to the XML (so good luck finding meaningful changes to an Excel file under all the dis…

git-MSOffice-diff

# /usr/local/bin/xmlzip.sh:
#!/bin/bash

for i in `unzip -Z -1 "$1"`; do
  echo "$i"
  unzip -a -p "$1" "$i" | xmllint --format -
done

# ~/.gitconfig:
[diff "xmlzip"]
        textconv = /usr/local/bin/xmlzip.sh

# .gitattributes:
*.xlsx diff=xmlzip
*.docx diff=xmlzip
*.pptx diff=xmlzip

Awesome! Can I suggest making it an actual project repo?

Good idea. I finally did that: Check gitMSOfficeDiff for any updates to this.