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.

gvanto

This powerful plugin allows you to insert HTML/Javascript code into your WordPress post’s content in a variety of different ways.
Using this plugin, you can specify pre-defined HTML code to be displayed at the top and bottom of all your posts, saving you valuable time. Merge fields let you pre-define HTML/Javascript that you can use anywhere in your post. For example, using [my_twitter] you can include an HTML link to your twitter account, anywhere in your WordPress post.
More more info and screenshots, please see: <a href="http://twoggle.com/wordpress-plugins/content-enhancer" rel="nofollow ugc">Content Enhancer</a> homepage.

Content Enhancer

This plugin allows you to insert html/javascript code into your post's content in a variety of different ways.

iSoftware Blocks vs Content Enhancer