For Drupal 7, see the Field group module, which includes tabs support.
Display CCK fieldgroups in tabs. Enables splitting up content onto tabs in both editing and display.
Note: if upgrading from the dev version to a stable release, ensure first that you have installed the latest stable release of Tabs.
To use, install and enable the module, then navigate to content type administration at
Administer » Content management » Content types. Create one or more fieldgroups for a content type and assign fields to the fieldgroup or use existing fieldgroups.
Each fieldgroup can be displayed on a tab. (It really only makes sense to do so for more than one, since a single tab serves no purpose.)
To get fieldgroups to display on tabs on content editing forms, select "tabs" as the "style" when configuring a fieldgroup under "Manage fields" for the content type in question.