NOTE: Joomla to version 1.0.13 has built in Search Engine Unfriendly URLs.
But, editing this in early March (and Nov) 07 - as just announced that next version, Joomla 1.5, will be capable of generating URLs that are:
permanent
readable
hierarchical
brief and clean
- a huge step forward, I believe. Info here: Joomla! 1.5 Accessibility - Look Ma no Itemid’s.
Here's info on Joomla to 1.0.13:
Although Joomla! 1.0.x has option for "SEF URLs", these are Search Engine Unfriendly URLs, as have Itemids at the end, and can have new Itemid - a new URL - for each additional link you create. Results in multiple URLs for the same content, which is an SEO no-no: you'll suffer duplicate content penalty (one page may do well in SERPs, but the lookalikes will be well down; plus dilute any pagerank from links to the content).
Best solution, had been OpenSEF.
OpenSEF
This was a wonderful component, but when there was argey-bargey re Joomla and contributions apparently having to use GNU licence, the developer, Predator, got pissed and promptly pulled down his site with OpenSEF forums etc - loads of contributed info, just gone; seemed Predator didn't give a monkey's about the community of users. But you can still download the component from joomlacode.org/gf/project/nusef/frs/. And, maybe OpenSEF will be revived (hmm, looks less likely by the day).
sh404SEF
There are several other options for creating SEF URLs.
ArtioSEF seemed tempting, but I read that it includes adverts. JoomSEF was version with the ads removed; but latest version included the ads.
After some time checking info, I decided to give sh404SEF a go. Tried it, and I like it. Gives some control over how the URLs are created (eg, here I use /category/aricle-title-alias.html). Has built-n ability to create SEF URLs with some important components, including Fireboard, which I've also switched to (from Joomlaboard).
Dreaming of Joomla with URLs that are both SEF - and Cool
I've posted to forums, inc re my wish list for URLs:
" Truly search engine friendly - ie one URL per item (no matter what link you follow to arrive there - via menu, a category listing, a sitemap...); easy for search engines to follow; with words if possible; and - also importantly - structured so that can keep the same URL even as upgrade.
Would also be more human friendly - I always feel better giving short links with words than raw cms type gibberish."
Also:
'Item on W3C is headed Cool URIs (URLs) don't change. Has some reasoning for this; also potential excuses - like "we just reorganized our website", "we had to move some files"... With top-notch URLs built into Mambo, wouldn't be extra excuses: "I run Mambo, and I just upgraded my Mambo version", or "I run Mambo, and just changed the way I generate URLs" '
Joomla forum has long thread on When will SEO be integrated? - much of it recalling Monty Python ("This isn't an argument, it's just contradiction"), and while some posts laughable, a few good - eg see by Predator on 3 October 2006. (Predator was developer of both Joomla! and OpenSEF)
I've made more posts; added copies to my forum on this site.