It's been a while since CiviCRM 3.3 went stable and the world around changed a bit: Drupal 7 and Joomla 1.6 were released. Since making CiviCRM work with new versions of these two CMSes required some backwards incompatible changes, we're releasing two versions of CiviCRM:
4.0.alpha1 for Drupal 7 and Joomla 1.6 3.4.alpha1 for Drupal 6 and Joomla 1.5Please remember this is an ALPHA release and it should NOT be used on production sites - however, we enourage you to install it on your test sites and let us know about any bugs or problems.
There are a few public sandboxes where you can try one (or many) of above versions:
CiviCRM 4.0 on Drupal 7 CiviCRM 4.0 on Joomla 1.6 CiviCRM 3.4 on Drupal 6