Justin Tadlock

Hybrid Hook is a plugin that allows end users the ability to tap into the <a href="https://wordpress.org/extend/themes/hybrid" title="Hybrid WordPress theme framework" rel="ugc">Hybrid theme’s</a> extensive hook selection by providing a user interface in the WordPress admin for adding custom content.
You must be using at least version 0.9 of the <a href="https://wordpress.org/extend/themes/hybrid" title="Hybrid theme" rel="ugc">Hybrid theme</a> for this plugin to work. It will also not work with any other themes.
Features:
<ul>
<li>Ability to add custom HTML nearly anywhere on your site.</li>
<li>Use shortcodes to quickly add content.</li>
<li>Allows the input of JavaScript.</li>
<li>User can select the priority the code will run.</li>
<li>Can execute PHP code if the option is selected.</li>
</ul>

Hybrid Hook

Allows the addition of HTML, shortcodes, PHP, and/or JavaScript to the Hybrid theme's hooks from the WordPress admin.

RMWebsec

Like a normal text widget this allows you to easily post text and HTML, but 
now you can execute PHP too! 
This makes merging with other themes easier.
!IMPORTANT! You must use tags for the code to be 
recognized.

PHP-Widgetify

Execute HTML, Text or PHP fast and easy with this Widgetify-widget.

Hybrid Hook vs PHP-Widgetify