Node displays is a replacement for the node build modes and the field / display settings screen provided by CCK. You can select per build mode which field is displayed, give it an order and render it in a node region. It is part of the Display Suite concept and is an implementation of its API.
Support and integration with core (search) and contrib (like CCK, fivestar and ubercart) modules is available at the Node displays contributions project.
We have documentation, screencasts and more information available. Go and explore the world of Display suite.
Version numbering between Display Suite modules is slightly inconsistent. Users of Display Suite 1.x should use Node Displays 2.x, but the last compatible version is 6.x-2.6, which you can download from its release page. 6.x-2.7 and above are only compatible with the 2.x branch.
The Drupal 7 version of Node displays has been merged into the Drupal 7 version of Display Suite.