The code structure of Less.php mirrors that of upstream Less.js to ensure compatibility and help reduce maintenance. The port is currently compatible with Less.js 2.5.3. Please note that "inline JavaScript expressions" (via eval or backticks) are not supported.
The LESS processor language is powerful and includes features that may read or embed arbitrary files that the web server has access to, and features that may be computationally exensive if misused.
In general you should treat LESS files as being in the same trust domain as other server-side executables, such as PHP code. In particular, it is not recommended to allow people that use your web service to provide arbitrary LESS code for server-side processing.
* **[Wikipedia](https://en.wikipedia.org/wiki/MediaWiki)** and the MediaWiki platform ([docs](https://www.mediawiki.org/wiki/ResourceLoader/Architecture#Resource:_Styles)).
* **[Magento](https://en.wikipedia.org/wiki/Magento)** as part of Adobe Commerce ([docs](https://developer.matomo.org/guides/asset-pipeline#vanilla-javascript-css-and-less-files)).
* **[Icinga](https://en.wikipedia.org/wiki/Icinga)** in Icinga Web ([docs](https://github.com/Icinga/icingaweb2)).
If you're looking to transition from the [Leafo/lessphp](https://github.com/leafo/lessphp) library, use the `lessc.inc.php` adapter file that comes with Less.php.
[Download Less.php](https://gerrit.wikimedia.org/g/mediawiki/libs/less.php/+archive/HEAD.tar.gz), unzip the files into your project, and include its `lessc.inc.php` instead.
Less.php can be used with [Drupal's less module](https://drupal.org/project/less) via the `lessc.inc.php` adapter. [Download Less.php](https://gerrit.wikimedia.org/g/mediawiki/libs/less.php/+archive/HEAD.tar.gz) and unzip it so that `lessc.inc.php` is located at `sites/all/libraries/lessphp/lessc.inc.php`, then install the Drupal less module as usual.
* [wp_enqueue_less](https://github.com/Ed-ITSolutions/wp_enqueue_less) is a Composer package for use in WordPress themes and plugins. It provides a `wp_enqueue_less()` function to automatically manage caching and compilation on-demand, and loads the compressed CSS on the page.
* [JBST framework](https://github.com/bassjobsen/jamedo-bootstrap-start-theme) bundles a copy of Less.php.
* The [lessphp plugin](https://wordpress.org/plugins/lessphp/) bundles a copy of Less.php for use in other plugins or themes. This dependency can also be combined with the [TGM Library](http://tgmpluginactivation.com/).
Less.php was originally ported to PHP in 2011 by [Matt Agar](https://github.com/agar) and then updated by [Martin Jantošovič](https://github.com/Mordred) in 2012. From 2013 to 2017, [Josh Schmidt](https://github.com/oyejorge) lead development of the library. Since 2019, the library is maintained by Wikimedia Foundation.