Well, the title pretty much says it all.
Some elaboration: I've tried the "official"
markdown utility. Another one is
markdown_py which is a somewhat more polished version of the former.
One of thing I'm very familiar with is
jekyll, but really I'd like something smaller. I just wanna throw out some HTML, not create a website. Most SSG:s tend to come with a bunch of dependencies, because... They're supposed to create static sites? Haha. So a utility, not a comprehensive program.