PowerPoint version control
The Office Open XML standards are a bit difficult to understand.
I'm going to take a presentation, perform simple operations on it (like add a line, etc.) and see what changes in the XML. That makes it easier to figure out how exactly the XML works.
The other advantage is that this gives a nice way of versioning Office documents.
expand.sh in the root folder shows how the XML files are
extracted and tidied up for comparison.