Differences between SMF 2.0 and SMF 1.1

Core Features

 * Core Features can now be enabled/disabled from a common page.
 * Advanced profile
 * Post moderation
 * Moderation logs
 * Paid Subscriptions
 * Warning System
 * Search Engine Tracking

Theme Management

 * You can now edit every template file on any theme including the defaul. (SMF 1.1 only allowed you to edit non-default themes files)

Permission System Changes

 * Permission system is now based on profiles.

Personal Message rules

 * Rules can be created to automatically sort incoming personal messages

Package manager

 * Package manager tries to apply changes to non-default themes too.
 * Emulate version for mod install/uninstall.

The New Default Theme "Curve"
Packaged since RC3 of the 2.0 series, is a new default theme called Curve. The original default theme, called Core, is still included with SMF 2.0.

Code related changes

 * support for PostgreSQL and SQLite
 * Integration Hooks
 * Better separation of theme and code (e.g. menu "definition" is now in Source.php so that is no more necessary to change each theme one by one to add or remove a menu entry)
 * $smcFunc

Unsorted

 * Scheduled tasks
 * OpenID
 * Mail queue
 * Languages installer
 * Verification questions
 * A default caching
 * Load balancing
 * ability to turn on/off signatures in admin panel
 * moderation center
 * birthday emails
 * additional attachments folders
 * edit meta description from admin panel
 * password strength
 * change forum width from the admin panel
 * WYSIWYG editor
 * install packages from a URL
 * three more group types: Protected, Requestable and Free
 * Reattribute User Posts
 * Remove Inactive Members
 * (maintenance) move all topics from a board to another
 * Buddy/Ignore lists (and related notification settings)
 * Personal messages rules
 * Display Personal messages all at once, one at a time and as a conversation