StackEdit: A free, open-source Markdown editor based on PageDown
What I want to see is an open source markdown editor that renders the preview as you type where you type (not side by side).For an example check out http://mangomarkdown.com/ (which powers foldingtext).There are a few projects that do this, but not open source, that I can find! It might not be that hard to change the current ones that go side by side to do this.(I am planning to work on one, but have not gotten around to doing much, and will probably take a different approach to it than this)