Reply to: by RyanBeesley

Historically you’re right. Earlier Word document formats weren’t actually document formats. One of the reasons Word was fast was that the .doc wasn’t a serialized version of the DOM, it was basically a memory snapshot of the data structures in memory. This made it unportable in that it would be very difficult to build a compatible editor to replicate or generate a compatible file. With the .docx format, Microsoft created a format that wasn’t bridled by memory structures in-file, and it could be read by other consumers of the document. This greatly increased interoperability so that it was easier to index content and exchange the file with other applications. These modern day Office files use an openly readable format that (while it isn’t free as in beer) is openly published for interoperability.