The Drupal to WordPress Migration Tool exports the bulk of the content from Drupal 6 to WordPress 3.5. It runs a series of MySQL queries to read information from a Drupal database and convert the content to WordPress. Please see this post for some background on the project.
A web front end is available for very basic Drupal installations. Sample SQL queries are included for more complex setups. It is an open source project released under The MIT License and hosted on GitHub.