WordPress Collaborative Editing | Matt Mullenweg

I'm guessing Google might not entirely agree with this description; see Introducing WordPress.com for Google Docs: A New Way Forward for Collaborative Editing (WordPress blog) for more details

"I think this is highly complementary to the work we’re doing with the new Editor in core WordPress. Why? Google Docs represents the web pinnacle of the WordPerfect / Word legacy of editing “pages”, what I’ll call a document editor. It runs on the web, but it’s not native to the web in that its fundamental paradigm is still about the document itself. With the new WordPress Editor the blocks will be all about bringing together building blocks from all over — maps, videos, galleries, forms, images — and making them like Legos you can use to build a rich, web-native post or page.

We’re going to look into some collaborative features, but Google’s annotations, comments, and real-time co-editing are years ahead there. So if you’re drafting something that looks closer to something in the 90s you could print out, Docs will be the best place to start and collaborate (and better than Medium). If you want to built a richer experience, something that really only makes sense on an interactive screen, that’s what the new WordPress editor will be for."

WordPress Collaborative Editing | Matt Mullenweg