revisions

http://drupal.org/project/content_moderation – complex, most sites do not need its advanced permissions, well maintained, does NOT allow handling of not-yet-published content in the same workflow. Even worse, you cannot use Drupal core capabilities to leave unpublished, review, and then publish, because it takes over these settings per content type.

git checkout old version
git get old copy
git branch checkout revision

http://stackoverflow.com/questions/849265/do-you-need-to-create-a-branch-to-check-out-a-specific-git-revision

basic git commands

Searched Words: drupal show authors of all node revisions multiple contributing users

Related how to for Drupal 5:
Adding 'Last edited by name some time ago' information
http://11heavens.com/adding-last-edited-by-name-some-time-ago-info-to-node