Most Linux apps do keep the formatting using the "text/html" clipboard format.
This is already supported by Notecase Pro.

ok, you typo'd on pun.  You had me kunfoozeded. 

Looks good. And it Python, so it gets +1 bonus points cuz it's hackable.

More pages should add this:

Can I enter a fake email address to register?

Sure. Actually, you don't need to enter an email address at all. You can just enter a desired username instead if you want, but you will never be able to recover your account if you forget your password and didn't enter a valid email address.

Still: the site really needs a free interactive demo but thanks for the link.

Thought I would add this one to the list. It is more of a journal than some of the others listed. I did a quick search and did not see that it had been posted about in the forums before.
For Linux, Windows (install or portable), even says Mac.

http://rednotebook.sourceforge.net/index.html

RedNotebook is a modern journal

It includes a calendar navigation, customizable templates, export functionality and word clouds. You can also format, tag and search your entries. RedNotebook is Free Software under the GPL.

    * Tagging
    * Spell Check
    * Format your text bold, italic or underlined
    * Insert Images, files and links to websites
    * Links and mail addresses are recognized automatically
    * Live-Search
    * Automatic saving
    * Backup to zip archive
    * Word Clouds with most often used words and tags
    * Templates
    * Export the journal to PDF, HTML, Latex or plain text
    * The data is stored in plain text files, no database is needed
    * Translated into more than 20 languages

There are a number of review links at the bottom of the screenshots page.  One person wrote his comparison with Evernote. One thing I like about it is it isn't "cloud" based.  Though he says you could via one of the 3rd party online storage sites.

Outwiker: http://jenyay.net/Outwiker/English#description

Source: http://www.outlinersoftware.com/topics/viewt/3831/

Haven't tried but from what was said, there seems to be a bug with adding text but the final post also said there was a new version released.