Joomla is a popular Content Management System and being a 
CMS means it does a lot of page creation in the background i.e. the site owner need not create actual html pages for the site.
As such, there isn't very much control the site owner has in making sure that the pages of a Joomla site are optimized for search engine ranking.
Mike Piper has written a good post on search engine optimization for Joomla sites over at SEOmoz, the SEO specialist web site. If you run a Joomla site you don't want to miss this article and as always there is some amazing information to be gleaned from the comments too...
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