New messages notification

For many years, the new messages notification appeared like this:

It was colloquially referred to as the "orange bar of death" or "orange bar of doom" (OBOD).

For logged-in users, the Echo extension replaces the original bar with the Echo bubble and a smaller notification bar (which temporarily replaces the link to the editor's User talk page):

The Echo new message notification looks roughly like this.

To see what the original (and still current for logged-out users) new messages notification looks like by default in various skins, use the links below. (The design in the version shown at the top, is from MonoBook/Vector):

You have new messages (last change).

Preview with available skins:

Userscript

Logged-in users who want to have the bar can use this userscript (for more info see en:Wikipedia:Userscripts and Manual:Interface/JavaScript): w:en:User:Writ Keeper/Scripts/orangeBar. For using it on projects other than en.wp you must change the importScript to the following:

mw.loader.load('//en.wikipedia.org/w/index.php?action=raw&ctype=text/javascript&title=User:Writ Keeper/Scripts/orangeBar.js');

(This loads it through ResourceLoader.) To enable it globally on all Wikimedia projects, add it to your Special:MyPage/global.js which is located on Meta.