Which technology do I use for a community portal site?

I have recently started with Wordpress, because I wanted to blog. I wanted to have more than that, though. I want my site to be involved as a community. What is the general rule of thumb between starting in scratch in PHP, or should I use Ruby on Rails? I heard that sites can be made quicker with frameworks more than starting in scratch. And then there are lots of content management systems out there: Drupal, Wordpress, Joomla, etc.
I want to have a forum, article section, reviews, screencasts, and more. What I don’t want is a social network similar to Facebook. I don’t want a friendship feature, since there are other networks for that. I want it wrapped around what my content will be. I have been considering using Drupal, but I’ve been considering others, such as Ruby on Rails, CakeCMS, Symfony, Yii, Django, and others. I want something that will not take me lots of time, but yet is highly programmable. Any and all comments about any of these systems and your thoughts, suggestions, and experiences are welcome!

P.S. It seems, based on my experience that Drupal is the most flexible for CMS and Symfony for a framework. For Ruby, Ruby on Rails, or Sinatra as a framework seems really good for flexibility. BrowerCMS seems to be the equivalent to Drupal for Ruby. I don’t want my opinion to be too biased.

You may try buddypress.org as it comes with all the features you want on your community website. Another alternative would be elgg.org that is a complete social networking open source software.

Thanks for that suggestion! This article confirms that Buddypress will be more flexible:

I also have some additional information I’ve found. Most articles I’ve read indicated that the more custom you get in your coding and away from these CMS systems, and frameworks, that’s when you would “start from scratch”. Facebook, for example, I was told was written in PHP. If I’m not mistaken, they’ve used custom coding directly in PHP that the frameworks and CMS systems didn’t have.
However, Twitter started out in Ruby on Rails, a framework, but switched to Cold Fusion, from what I understand. They claimed that Ruby on Rails “didn’t scale” at the time. Ruby enthusiasts laugh at this, because technology has a habit of getting better. The next thing you know, they fixed that problem! Apress puts out some good books on things like Web 2.0 and Social Networking, if you want to custom code without any frameworks or CMS software. Eventually, I may getting to review these kinds of books.

I would request don’t go for frame work. If you wish to start a blog or website then use wordpress as CMS as it is easy to handle. Joomla and drupal are also good but i prefer wordpress. Use php for back end in any case. The problem with using frame work is that it take too much time to understand the code written by other programmers.