OpenSEF is a Joomla 1.0.x component that extendes Joomla's SEF (Search Engine Friendly) URL mechanism allowing you to define arbitary, friendly URLs for any of Joomla's content and component items.

Now, instead of non-readable URLs such as: http://www.mysite.com/component/option,com_frontpage/Itemid,1/

You can have addresses such as: http://www.mysite.com/welcome.html http://www.mysite.com/NewCars/2005/CorvetteC6.html