Was to find a documentation link for to help a user remove the "Powered by" and the "Joomla! is free.." and found this Faq article.
Think this has to be rewritten, as the title refers to one case and the content of this Faq to another case. The title indicates this is about how to remove the "Powered by" (which is done by editing the template index.php (or in case you just want to edit part of the text its handled in the en-GB.ini for the strings 'Powered by' and 'Valid')). But the content of this Faq item tells how to Edit the footer text, which is something quite different.
So this probably should be split in two Faq items. 1. Can you remove the "Powered by Joomla! message? - with content explaining how to edit for example rhuk_milkyway:
<?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>.
and 2. Can you remove/edit the "Joomla! is Free Sotware.."? - with content telling how to A) easily deactivate the footer module (Extensions->Modules->Click 'Footer'->Unpublish), or to B) edit strings in en-GB.mod_footer.ini or the xx-XX of your preferred language.
Just my 2 cents. Ole