Code Soup

The Web Archive plugin for WordPress provides a simple yet powerful way to create HTML copies of pages or any post type upon their publication.
This functionality allows website owners and administrators to keep track of all previous versions of the same page or post, ensuring that changes, updates, and iterations are recorded and retrievable at any moment. 
This is especially useful for content management, auditing, and compliance purposes.

Web Archive

Automatically creates HTML copies of your posts and pages when they're published, allowing you to track every version.

Paul Menard

Provide Versioning, Preview and Rollback ability on Pages and Posts.
<a href="http://www.codehooligans.com/2008/04/18/versioning-your-blog-content/" title="Versioning Your Blog Content" rel="nofollow ugc">Plugin Homepage</a>
<h3>Version Histroy</h3>

1.0 – 2008-03-16: Initial release 
1.1 – 2008-03-21: Fixed slight error in INSERT SQL for the new Revision. Also fixed escape on inserted content. 
1.1b- 2008-04-04: Changed the ‘post_status’ value on the saved revision to ‘inherit’ as this was causing problems with some other plugins. 
1.1c- 2008-04-17: Added notation to indication current version. 
1.2 – 2008-04-18: Changes to Admin display section to make things work under WP 2.5 
1.8 – 2008-05-04: changes to enhance WP 2.5 design integration. Added ability to delete revisions, set a no revision ‘minor-edit’ option, set a no revisions for life checkbox. Display on last 5 revisions with link to reveal more. 
1.8.3 – 2008-05-23: Minor changes to display. Added link to reload most current version of content.

Revisions

Provide Versioning, Preview and Rollback ability on Pages and Posts.

Web Archive vs Revisions