Masahiro NAKASHIMA

The theme can be changed and displayed to only logged in users.
The visitors of the website see your old theme while you are testing the new one.
Only the administrator of the WordPress site sees the new theme that can now be tested safely.
You can also use this plugin instead of “Theme Test Drive” plugin.

WP Theme Test

I have xdebug installed. There are two big Notices.

Threw two big PHP notices

The theme can be changed and displayed to only logged in users.

thom4

fabrizim

<a href="http://lesscss.org" rel="nofollow ugc">LESS</a> is a templating language based on top of CSS. It provides numerous enhancements to speed up development and make its maintenance easier.
Theme developers can even bundle the plugin without worrying about conflicts: just include the special <code>bootstrap-for-theme.php</code> and read its instructions.
<h4>Features</h4>
<ul>
<li>Variables</li>
<li>Mixins (inheritance of rules)</li>
<li>Nested Rules (write less, do more)</li>
<li>Accessors (inherit a value from a specific rule)</li>
<li>Functions (logic operations for dynamic results)</li>
</ul>
The plugin lets you concentrate on what you need: coding CSS. Everything else is handled automatically, from cache management to user delivery. 
Seriously.
<h4>Documentation</h4>
Advanced topics on how to use the plugin API are <a href="https://github.com/oncletom/wp-less/tree/master/doc" rel="nofollow ugc">available on the Github project documentation</a>.
<h4>Requirements</h4>
The sole requirement is to use WordPress API and LESS convention: the <code>.less</code> extension.
Minimal Requirements: PHP 5.3 and WordPress 3.2. 
Relies on: <a href="http://lessphp.gpeasy.com/" rel="nofollow ugc">Less.php</a>, <a href="https://wordpress.org/extend/plugins/plugin-toolkit/" rel="ugc">plugin-toolkit</a>.
Notice: in case you’d like to drop the usage of this plugin, it’s safe to do it. You will just need to convert back your stylesheets to CSS.

WP-LESS

Implementation of LESS (Leaner CSS) in order to make themes development easier.

WP Theme Test vs WP-LESS