Carsten Jonstrup

The PHPEval Plugin is a WordPress plugin which allows users to write php code inside of their pages. Embedded php code will be executed when the post is shown. In doing so, the plugin offers the possibility to utilize dynamic content inside of posts. In contrast to other plugins with the same aim, this on is focus on security. Here’s a features list:
<ul>
<li>Easy to setup and configure</li>
<li>Simple syntax</li>
<li>Central administration of code</li>
<li>More coming up soon!</li>
</ul>
YES, I do consider feature requests, and that is what makes this plugin work. The discussions go here: <a href="http://code.google.com/p/phpeval/" title="Technical Support" rel="nofollow ugc">Technical Support</a>

PHPEval

The PHPEval Plugin is a Wordpress plugin which allows users to write php code inside of their pages. Embedded php code will be executed when the post  …

Sharaz Shahid

Code Widget is simple widget allows you to insert any arbitrary Text/HTML and run PHP Code or Short Code. This Widget parses PHP code into simple text and much more.
Only users with the unfiltered_html role will be allowed to insert unfiltered HTML. This includes PHP code, so users without admin or editor permissions will not be able to use this to execute code, even if they have widget editing permissions. 
This plugin is developed and maintained by <a href="https://twitter.com/sharazghouri1" rel="nofollow ugc">Sharaz Shahid</a>

Code Widget

Code widget help  to  add  Short Code, PHP Code, HTML, and Simple Text in widget.

PHPEval vs Code Widget