Live Writer allows you to connect to Wordpress, Blogger, and other online blogging platforms. You can import posts from your blogs. You can compose in Live Writer (similar to you compose in Word). You can send your composition to your Wordpress blog as a draft, or even publish from Live Writer.
How does it communicate with Wordpress (in terms of, if I was to code something similar, what would be the points of action)?
Also notably, Live Writer is able to retrieve the categories list from WordPress! How does it take this from WordPress and embed it on Live Writer?