The markdown editor component is available under a free software license and the about dialog on the editor page has not been modified in any way.

When you say "better commented" I have to wonder what you mean - if you're talking about comments in the HTML and JavaScript then you'll have trouble reading them as the server minimises all content before sending it to the user's browser in order to save on bandwidth costs. This is done using a combination of python htmlmin and Yahoo's yui-compressor and I encourage you to look into these tools - neither is designed to obfuscate, just to remove whitespace etc in order to make the file smaller.

It is not plagiarism to reuse code that the author licensed you to reuse - in fact it's a practice done by just about all good developers. I responded to a similar comment on the original announcement post pointing out that the site also makes use of Debian GNU/Linux, nginx, web.py and Python - none of which I am the author of, but I never claimed to be.

I am however author of the FastCGI web.py process that serves up the content, the javascript for local drafts, the sample markdown, the API and the other pages on the site.