Dynamic URLs and SEO don't always meet well

Looking from a CMS (content mangement) perspective

In an ideal world, one would check the capabilities of any CMS were adequate before emabarking on building out with the solution. Once you've gone down the road of building out content using the solution, if you find the URLs and SEO capabilities are lacking, changing systems could be a difficult road to travel.

For example, if you've created lots of content, and the URL structure of the new system is different, you would have to create redirects for all the content from old to new. Secondly, you would have to get all that content out of the old solution and into the new, depending on the import and export capabilities of each system this could be quite a bit of work.

At the moment we use a custom built CMS solution for this site, we have built it up to generate proper meta tags and generate clean URLs with few parameters. If you are looking for a CMS based on Java / Grails then we think that Weceem is a good choice; further all our new sites are being built on it and we will contribute to it.

If you are looking for a PHP / Apache solution, I would take a look at Drupal, it has a large following and lots of available templates.