my solution is using web client with browser. one embarrass is that web client do not support paste content with html format, like layout, color and so on. Then I found this extension "markdown here" for firefox. after installed this extension, just select your text (written with markdown format) in evernote web client, right click, select "markdown toggle", then your content will be rendered. I think it's the most elegant solution for ubuntu so far, you can even rendering source codes and other markdown supported rich text. This extension also supports chrome, but in my Chrome under Ubuntu It doesn't work, only works with Firefox.