I've been using this for a while (at least a year or so) and it's by far my favorite markdown editor. I love the side by side panes (code + preview) and the ease of use. It stays out of my way while I write.<p>I write Markdown for my blog and depending on what I'm doing, I like to write while I'm doing it, (to verify each step of a tutorial) which means I had to find a MD editor for 3 platforms (Windows, OSX, Linux). This one is by far the easiest, most reliable offering out of the three. The side by side preview is great.<p>I've used Uberwriter too, which would be great for a different kind of writing. Since I'm usually going through some steps of a tutorial I use a lot of images and code markup and it doesn't really handle this well. If I were writing a novel or article however Uberwriter works pretty great for that.