I’m making a rare post seeking suggestions for software. I’m starting up a site for utilitarian purposes (ie, not a blog) that’s meant to be a centralized repository of useful information. What I need is:

1. Some sort of content delivery system that looks professional (or can be made to look professional)

2. Is easy to update, maintain and design

3. Is not some blog/hybrid kluge but was purpose built for the task

4. Is easy for a user to navigate between sections and categories and perhaps submit information of their own

5. Preferably open source, but not really required.

I can do the thing in Flash and make it do what I want to do, but I need something non-Flash based to serve people who want something traditional.