Good idea. If you run `proselint` without specifying a document, it'll run on the demo text, which you can also access here: https://gist.github.com/suchow/c7856f21128aee89ad55. Also, there's a live demo available at: http://proselint.com/write. It's been tested only on the latest version of Chrome, and I doubt it will handle the load here, but give it a try.