This documentation covers the 1.x version of Integrated Metatags.
Integrated Metatags was originally designed as a contrib module for Drupal 6. By request, a back-port for Drupal 5 was created. The Drupal 6 version of this module has an option to display Metatags when nodes are rendered as a teaser, an option missing in the Drupal 5 version. Aside from this one feature difference, the Drupal 5 and Drupal 6 versions are functionally identical.
Future development will continue in a 2.x branch of the Drupal 6 version. Bug fixes will continue to be applied to the 1.x Drupal 5 and Drupal 6 versions, but no further feature development will happen in the 1.x versions. Once Drupal 7 is released, I intend to port the 2.x version, or will only release it for Drupal 7 depending on timing. The 1.x versions of this module may also be ported to Drupal 7 if there is enough demand for it, or if Drupal 7 is released prior to the 2.x version is completed.
What's the difference between this module and the Nodewords/Meta tags module? The Nodewords module has a lot of functionality built into it, providing a much broader range of control over Metatags. However, I disliked that it required you to populate a field for your Metatags in each node form. I figured there had to be a better way to dynamically generate the Metatags without having to manually enter them for every node. I then created the Integrated Metatags module, which allows you to configure Metatags at the content-type level. By abstracting the Metatag settings to the content type instead of the node, and by exposing node properties for generating dynamic Metatags, the Integrated Metatags module allows for a broad range of Metatags.