iSoftware

Blocks lets you create your own reusable blocks of content where you can use shortcodes to insert code snippets, HTML including forms, iframes, etc and control formatting.
You can insert Blocks into pages, posts, widgets or directly into php content.
It is ideal for inserting reusable objects into your content that you can use side by side or as an alternative to standard posts.
It is fully compatible with WPML for content translation and WP Views for content filtering.
Configurable Features:
<ul>
<li>The “Output Mode” setting to control whether block content is rendered adding paragraphs and line breaks (wpautop) or not.</li>
<li>The “Sort Order” setting to control sort ordering when quering for a list of blocks.</li>
<li>The “Block Widget” that allows you put a block in any widget area on your site.</li>
<li>The “Multilingual Block Widget” that extends the normal “Block Widget” to work in a multilingual context with WPML (requires WPML plugin and Block Type Translation enabled).</li>
<li>The “isw-block” shortcode enables a block to be embedded in any post on your site.</li>
</ul>

iSoftware Blocks

This plugin lets you create your own reusable blocks of content.

Felipe Lavín

This plugin adds an editor button that will let you use the great <a href="http://codemirror.net" rel="nofollow ugc">CodeMirror</a> editor to edit the HTML code of your posts.
This editor supports code coloring and automatic tag closing on a big editor that will let you write beautiful code on your WordPress posts.
Probably the best choice if you need to use complex HTML on your posts, or just enjoy writing in plain HTML.

CodeMirror for Post Editor

Write beautiful HTML code using the CodeMirror component for your WordPress posts.

iSoftware Blocks vs CodeMirror for Post Editor