Search Engine Friendly Mambo and Joomla
Mambo and Joomla are probably newest and most exciting open source available today. However as with every open source their core lacks some real SEO work which should have been present.
The default search engine friendly URLs feature is optional in both CMS and has specific pre-conditions. It needs to have the site be hosted on apache only server with mod_rewrite enabled, .htaccess override enabled.
Even after getting this working, all you get urls are like http://www.yourdomain.com/section id/cat id/content id. This is not enough search engine friendly as it misses out the title of article in URL.
Thanks to opensource community, there are separate open source solutions available to finish the unfinished job in core mambo/joomla. I have personally used OpenSEF. OpenSEF component enables one controll the SEF URLs manually or automatically.