WordPress is an popular blogging and publishing platform which users can build advanced functionality into their sites with plugins. If you’re interested in building a community around your site, here are some Wordpress Plugins that might be useful if you are setting up your own site that can help you create a community/directory/membership site and your content.
14. WP-Sentry: Users may be members of multiple groups. Multiple groups and multiple individual users may be allowed to view each post. Overlaps are ignored — if the user is a member of any group that is allowed to view the post, that user will be able to view it.
16. Digress.it: lets your visitors add notes in the “margins” of a blog post, much the same as one would in a book. It can be used in an educational setting, to annotate a post, or even to offer criticism.