Role Scoper is a comprehensive drop-in replacement for capability enforcement and administration in WordPress. Assign reading, editing or administration roles to users or groups on a page-specific, category-specific or other content-specific basis.
wpSEO [EDIT] Link removed since it is a paid plugin.
The wpSEO plugin helps you optimize your blog for SEO purposes by eliminating issues with duplicate content and specifying meta tags and page titles for the different pages of your blog. Page is in German. English and German files are included in the download
The Plugin looks for related posts from the same categories as the current article. With numerous customization of the call to function. Page in German