k0tik

<p>The usual Text widget allows you to insert arbitrary Text and/or HTML code. This allows that too, but also parses any PHP or JavaScript code in the text widget and executes it.</p>
<p>This plugin is based on “PHP Code Widget”, but now available for use by site administrators ONLY, which makes it more secure.</p>
<p>All PHP code must be enclosed in the standard php opening and closing tags ( <code><?php</code> and <code>?></code> ) for it to be recognized and executed. Also JavaScript code must be enclosed in the <code><script></code> and <code></script></code> tags, as usual.</p>


Safe PHP Code Widget

Adds a secure and simple widget in which you can use PHP and JavaScript code. Also you can use unfiltered HTML or just Text. Admin Use Only.

Stephen AfamO

<p>This plugin allows you to use any HTML or PHP file as the template for any page or post.</p>
<p>Simply upload the file and select it.<br />
You can upload custom js and css files into the media library and link to them from the HTML file.</p>
<p>Options:</p>
<ul>
<li>Overwrite All: You overwrite the entire theme and use your custom file</li>
<li>Overwrite Content: Keeps the header, footer, sidebar, e.t.c. Simply overwrites the body of the page or post</li>
<li>Above Content: Your custom content is simply added to the top of the page content</li>
<li>Below Content: You custom content is placed just beneath the page content.</li>
</ul>
<h4>Adding support for custom post types</h4>
<p>By default the pulugin works with pages and posts, however, go to the settings to enable it on any other registered post type.</p>
<p>use the <code>hppp_post_types</code> filter to add more post types.</p>
<p>Like this:</p>
<pre><code>    public function post_type_modify ($post_types) {
        $post_types[] = 'custom_post_type';
        return $post_types;
    }

    add_filter( 'hppp_post_types', 'post_type_modify' );
</code></pre>


Custom HTML/PHP Post Templates

I use this on a couple sites I own and it works wonderfully.
I hope you can find it useful. 

Works like a charm

Use your HTML or PHP files for any page or post.

Safe PHP Code Widget vs Custom HTML/PHP Post Templates