Hi
1 - tags? what sort of tags? Joomla does provide a Tag component, is that what you talk about?
2 - Glossary: no. That's a topic in itself, and there are extensions for that.
3 - Internal llinks. Don't understand what you mean, what the question is.
4 - Sitemap: it's a project, but again there are extensions. I can say it'll surely happen, as a separate plugin, but there are issues to be solved, namely:
- how do you exclude/include links from the sitemap (other than manually clicking on each link in the URL manager)
- speed
Basically, a sitemap is useless for small sites (from an SEO standpoint) and very hard to do for a large site...
Rgds