I tend to use more and more NetBeans as my cross-platform editor of choice.
Mostly because it shines for web development and has a pretty good support for Git.
Just one thing was lacking: the support for Markdown syntax when editing files.
This plugin is available on Github and can be installed directly. Just get the nbm distribution.
In settings, you can enable some extensions to standard markdown, such as tables or Wikilinks.
I’m testing it, but it seems pretty good for now.
Give it a try.