Marcus Downing

Adds an “Identifier” column to the All Posts and All Pages admin panels, and to any custom post types. 
This column goes just after the Title column and shows each page’s slug, indented if necessary.

Page Identifier Column

Adds an "Identifier" column showing a post of page's slug, just after the Title column.

macguru2000

TRUEedit is designed specifically for people who understand HTML and want to format their HTML code for readability. By default WordPress modifies your post content with two filter, this plugin lets you disable those filters along with any other content filters. TRUEedit also enables the inserting of tab characters into the post’s content editor. You can even change the font, size and color of the editor, giving you more control over your blog editor.
Keep in mind that by default WordPress texturizes and automatically adds break and paragraph tags into your post content. Which means if you want to put HTML tags on different lines and format your code you could inadvertently be adding break and paragraph tags. Oh No? Use TRUEedit to fix this problem.
Highlighted Features:
<ul>
<li>Removes the wpautop filter which adds paragraph tags to your post content.</li>
<li>Removes the wptexturize filter which replaces characters and patterns.</li>
<li>Review and remove any other filter applied to the content of your blog.</li>
<li>Lets users insert tabs in the post HTML editor</li>
<li>Lets user change font, size, color and height of the post editor</li>
<li>Lets user go into a fullscreen editor mode.</li>
</ul>

TRUEedit

TRUEedit turns the Post HTML Tab into a raw HTML editor that does not texturize or modify your code.

Page Identifier Column vs TRUEedit