Recently I've been helping a few folks migrate websites from WordPress to Drupal. Presently this works for migrating to Drupal 5 so if you want a Drupal 6 site first migrate to Drupal 5 and then upgrade the site to Drupal 6.
The mission of this site is to help web site developers who are considering or using Drupal. Drupal is a very powerful content management system using php and mysql. There are hundreds of modules and themes available, but instructions for most of these ar