http://drupalcontrib.org/api/drupal/contributions!ctools!includes!object-cache.inc/7The non-volatile object cache is used to store an object while it is being edited, so we don't have to save until we're fully finished. The cache should be "washed" on a periodic basis, meaning to remove ancient items from the cache, but otherwise the information in this cache must stay stable, as it contains unsaved modifications.
Building Multistep forms using the Drupal 7 CTools object cache
name = MultiStep
description = Custom Multistep form module.
core = 7.x
dependencies = ctools