Wow - I had no idea.
I might look at that Sublime Text setup for Markdown - I like that it's cross platform.
-mwb1100
Yes, its in use in quite a few applications on windows and cross platform. If you're looking for cross platform and don't mind web based, I'd also be remiss if I didn't mention the ones that I'm using:
Markable - has an HTML to markdown converter which can be useful. Also has some other pretty cool features.
Dillinger - Live changing of markdown flavour.
Draft - Made with a real focus on writers, and collaboration on that writing. Just started using it, but the developer seems really responsive.
StackEdit - side by side live preview
All of them import/export/sync to/from dropbox, evernote, google drive, etc... in some form or another. I was skeptical, until I needed a quick way to edit on a few platforms in a hurry. Tried stackedit, and it was great for that. Synced up to google drive and drop box. Viewed the output in Texts and exported using that to word. Also used in Visual Studio as what I was doing was auditing code, which made it great to keep the workflow integrated.