1. Module based solution - and there is no strict rules in module creation
2. Build in user management system - this system includes basic registration / password restore / profile functionality. Also user/groups/permissions management in administrative area
3. Build in access control lists - you should not care about access isolation while developing new functionality. ACL could be tuned after you finish
4. Content management system - you could manipulate site content and menus easily
5. AED tools - allows to create add/edit/delete panel for whatever entity in minutes. Was created to build administrative interfaces but could be used anywhere.
6. Layout tool - allows to create logically separated controllers. So for instance your registration controller will perform registration logic ONLY.
7. View themes support - allows to create your own themes and there is no strict standards for it.
8. Build in form validation tool - performs both client and server side validations.
9. Form builder tool - allows to generate forms with standard or custom fields
10. And many other functionality like controller and model for trees, mailing tool, SEO tool, SEO friendly URLs, file uploader, easy built pagings, cache tools, db profiler, full AJAX support powered by jQuery etc.