This is version 2.6 of Subscriptions for Drupal 6.
The purpose of this release is to move a feature that has been sitting in -dev version for half a year into a proper release and to close the -dev snapshot. You don't need to update unless you want this feature.
Changes since 2.5:
- #735092: Backport #560146 from D6: Allow specifying a cron job time percentage (including 0 to temporarily disable notifications).