I came across this program in the Outliner Forum. I downloaded and tried it. It lives up to its promises (which are minimal), using Markdown as wiki markup and storing its files as plain text files.
What I like about it most is that it uses free links, i.e. Double square brackets, like "[[this]]" for links. It's using "io.js and Electron", whatever that means. The one I downloaded is "version 0.9 Released July 7th 2015".
They say: "Malkovich is a desktop application built to run on your computer. It's self-contained and easy to install. You don't need to mess around with databases and run servers."
One problem, I have not been able to figure out where the data (or files) are actually stored (even though the Website says: "Notes are all stored as markdown formatted text files on your computer"). Accordingly, I have uninstalled it again.