karevn

This plugin adds simple HTML tag generation API to WordPress, like these examples: 
 generates and prints <code><img src="/wp-content/<your-theme>/images/wordpress.png" alt="Wordpress" /></code>. 
 ‘my-image’)) ?> generates and returns almost the same tag, just with absolute url, id and alt attributes set manually. 
 term_id) ?> generates select tag with options taken from WP ‘category’ taxonomy and sets $term as selected item 
 rails-like “cycle” that returns “odd” on first call, “even” on second, “odd” on 
 third call, so on. reset_cycle resets the cycle. 
 shortcut for echo(get_post_meta($id, ‘meta_name’, true))
Form field generators for <code>text</code>, <code>checkbox</code>, <code>hidden</code> input types, <code>textarea</code>, and more tags. More docs coming soon, you can read the code to figure out other features for now.

HTML Helpers

This plugin adds simple HTML tag generation API to WordPress.

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.

HTML Helpers vs PHP-Widgetify