4.0.7 - 2 June 2015
In addition to many bug fixes and performance improvements, some specifics include:
Fix for update checker not working
Search index efficiency improvements
Guest caching feature can now be used with MySQL (previously required a caching engine like memcached)
Fix for common problems with queue task locking
Topic-view loading efficient improvements that should also improve loading on iOS devices
Sorry, but you need at least 25 posts and 5 hours online time to unlock hidden content.