Mark Jaquith

Michael Adams (mdawaffe)

Other preview plugins don’t know what sort of changes WordPress will make to a 
visitor’s comment, but this plugin uses AJAX and other buzzwords to send each 
previewed comment through WordPress’ inner voodoo.
The result? With the click of a button, your site’s visitors can preview their 
comments exactly as they will appear when they submit them for realies.
Requires PHP5.

Ajax Comment Preview

Visitors to your site can preview their comments with a click of a button.

Christopher Finke

Inline Preview is a plugin for WordPress that adds a live preview of the current post next to the post editor instead of opening the preview in a new tab.
Problem: When creating a post in WordPress, previewing your post in a separate tab can be slow and/or complicated.
Solution: Show the preview right next to the editor.
It’s just an idea I’m playing with for streamlining the post creation process, and if it feels familiar, it’s probably because it is: through version 2.1, WordPress contained a preview iframe at the bottom of the post editing screen, but this is a more elegant implementation.

Inline Preview

Inline Preview adds a preview of the post you're writing next to the editor when you click Preview (instead of opening it in a new tab).

Ajax Comment Preview vs Inline Preview