Raihanul Islam

WordPress Random Post plugin is a small but very smart solution for your WordPress web site. It allows you to show posts in a random order in a sidebar. You can display simultaneously as many random posts as you need with chosen effect and delay time.
<h3>Arbitrary section</h3>
You may provide arbitrary sections, in the same format as the ones above. This may be of use for extremely complicated 
plugins where more information needs to be conveyed that doesn’t fit into the categories of “description” or 
“installation.” Arbitrary sections will be shown below the built-in sections outlined above.
<h3>A brief Markdown Example</h3>
Ordered list:
<ol>
<li>Some feature</li>
<li>Another feature</li>
<li>Something else about the plugin</li>
</ol>
Unordered list:
<ul>
<li>something</li>
<li>something else</li>
<li>third thing</li>
</ul>
Here’s a link to <a href="https://wordpress.org/" title="Your favorite software" rel="ugc">WordPress</a> and one to <a href="http://daringfireball.net/projects/markdown/syntax" title="Markdown is what the parser uses to process much of the readme file" rel="nofollow ugc">Markdown’s Syntax Documentation</a>. 
Titles are optional, naturally.
Markdown uses email style notation for blockquotes and I’ve been told:
<blockquote>
Asterisks for emphasis. Double it up for strong.
</blockquote>
<pre><code><?php code(); // goes in backticks ?>
</code></pre>

Awesome Random Post

Here is a short description of the plugin.  This should be no more than 150 characters.  No markup here.

WP Chill

Silkalns

Cristian Raiber

A very useful plugin for everyone using WordPress. Adds reCaptcha security to the WordPress login form, register form and comment form. This plugin could help your blog get rid of a lot of spam comments or brute-force attacks.
Nothing gets passed it if the reCaptcha doesn’t validate.
A few notes about the plugin:
<ul>
<li>Supports audio or image captcha types</li>
<li>Can generate the reCaptcha image / audio type in a number of predefined languages</li>
<li>Adds reCaptcha protection to the WordPress login form</li>
<li>Adds reCaptcha protection to the WordPress register form</li>
<li>Adds reCaptcha protection to the WordPress comment form</li>
<li>Adds reCaptcha protection to the WordPress recover password form</li>
</ul>

Uber reCaptcha

This plugin adds the reCaptcha form to the WordPress login form, recover password form, register form and comment form.

Awesome Random Post vs Uber reCaptcha