alt Hacker NewsIs it really so different in the service context? You could also reverse engineer the HTTP endpoints and formats used by Word Online to export data from the service. It doesn't feel all that different, except perhaps that the online service can try to detect your custom tooling and block you, whereas with static data that isn't possible.
But other than that admittedly real extra problem, the bulk of the work would still be understanding the undocumented protocols and feature semantics, then matching the feature set.
Hmm, Word Online isn't what the article is about. I'm not sure if you've read the article, but it is about social apps — like Tumblr, Reddit, HN itself, etc.
I'm using file formats as a metaphor to explain how apps built on AT protocol work (lexicons are like "social file formats"), and what this way of building enables (interoperability between social apps by default).