Joomla! was released under the GNU/GPL License which means you can indeed clean up the generated code of your website from any Joomla! related links and copyright information. Still you should know that you may not remove them from the source code itself e.g. from the PHP files on your server.
1. To clean your website footer by removing “Powered by Joomla!. Valid XHTML and CSS.” and any other possible copyright notices:
Go to your templates/index.php folder and at the bottom of the page you will find the code you need to remove or edit.
1 2 3 4 5 6 7 8 | <p id="power_by"> <?php echo JText::_('Powered by') ?> <a href="http://www.joomla.org">Joomla!</a>. <?php echo JText::_('Valid') ?> <a href="http://validator.w3.org/check/referer">XHTML</a> <?php echo JText::_('and') ?> <a href="http://jigsaw.w3.org/css-validator/check/referer">CSS</a> </p> |
2. By default you will find the Metadata of your pages having Joomla! related information. So, one
more important thing you need to do is to change that:
First edit the Metadata Settings of your site from the Global Configuration page in your Joomla! Administration CP.
Then in your templates/index.php folder add the following line exactly before the <head> tag:
1 | <?php $this->setGenerator('Write anything here'); ?> |

Appreciate this. Really interesting article.