Acquia: Commercially supported Drupal
When it comes to choosing a content management system (CMS), the open-source Drupal is often a great choice for large or content-rich sites, because it scales well, supports multiple authors and is thoroughly customizable. The downside of all of this power is that for new users especially, the learning curve can be pretty steep. Although Drupal 6 was a huge step forward in overall usability, from a web admin perspective, it's still not exactly easy.
Acquia, a company founded by Drupal creator and project lead Dries Buytaert, has just launched Acquia Drupal, which packages Drupal and some of the most popular and highly rated community modules together and also offers commercial support. This is a big win for both Drupal and current and future Drupal users.
Acquia Drupal is a free GPL-licensed download. It contains the Drupal 6.x core (currently at 6.4), a bunch of community contributed modules, like Google Analytics, Mollom (Dries's spam-fighting content solution), and rating and image gallery tools. I installed Acquia Drupal on my local test server and also installed the latest Drupal release, 6.4. The install process was already easier with Acquia Drupal, because I didn't have to create a settings.php file in advance before filling in my database details.