A number of features have been moved to modules or blocks such as the Member List, Private Messages, Who Is Online, View Online, Mass E-mail (ACP) and DB Utilities (ACP).
A number of the new core features have been added or existing features enhanced. Security and performance have been foremost in my mind during the design (or R3-design as I call it ;-)) of R3-born. There a more optimizations to come.
Installer
R3born has an enhanced Installer which can detect operating requirements and file permissions and auto detects cookie settings.
Template Engine
The template engine been optimized significantly, it now caches, adds new features to make handling content from blocks and hooks much easier (for a developer) and adds logic (IF, THEN, ELSE, etc) to the templates.
The ACP navigation has been improved with collapsible panels and the ACP templates have been separated so they are standalone. This means style designers do not need to duplicate ACP templates anymore.
Where possible Javascript has been separated from the templates so style designers don't have to reproduce the same Javascript over and over and additionally page loading/caching is improved.
There are no global images in R3-born, images are linked styles. This means that style designers can ensure all the images will match the look and feel of their web design.
Significant work has been done to improve the cross browser compatibility of the templates, especially when posting or editing content but a fix for PNG images with transparent backgrounds for IE 5.5 and IE 6.0 has also been added to help style designers insure their web designs look how they intend.
The subAndreas style replaces subSilver and will eventually be a clean CSS2/XHTML implementation that fully validates. Is it far from complete right now.
Sessions
The sessions handling code has been integrated with the module engine such that page id's are atomically assigned (nor more PAGE_ defined constants) and sessions are search engine optimized for guests.
Sessions are updated correctly on each page load (rather than every 5 minutes) to given more accurate feedback when viewing who is online.
Styles can be made persistent via a URL parameter or cookie. Eventually this will integrate with a planned Search Engine Indexer detection engine so that Search Engine Optimized pages can be dynamically delivered to search bots.
User Management
R3-born has Junior Administrators, these are users who can be assigned administrative permissions to any ACP panels or sub-panels to help the administrator manage the site.
A simple User API has been created which will be extended in the future. Right now it provides a simple way to create and delete user accounts. User deletion is Hooks enabled so that any Blocks or Modules which need to remove or modify data when a user is added/deleted can do so.
Users can choose to "Self Delete" their accounts if they no longer want to remain a member of the site.
The User Profile features have been overhauled including an improved captcha image, simplified registration form, e-mail address confirmation, hook integration so modules and blocks can add custom profile fields which are editable not only by the user but also in the ACP.
The Login page has been updated considerably with many new features such as re-sending activation codes, forgotten passwords and forgotten user names, etc.
Group Management
Groups have been extended so that groups can have moderators and colours assigned to them. If a user is a member of many groups they can pick the group they prefer to be most closely aligned with and their user name is colourised accordingly.
Policies
R3-born has several polices including Terms of Use, Privacy Policy, Site Rules, etc. These are all editable via the ACP (HTML only), displayed as appropriate when registering to the site and also in the page footer.
Security
New functions to handle POST and GET variables have been added which better secure these variables. A basic intrusion prevention system (no logging) has also been added to fend off the most common web attacks.
The banning system has been enhanced, with more improvements planned. The HTTP_REFERER and HTTP_USERAGENT variables are sanitized and added to $userdata. This will help prevent code injection attacks for Blocks or Modules which might need to use those variables in the future.
These are by no means the extent of the efforts, more work is planned.
Time and Date
R3-born supports daylight savings, which are editable by each user in their Profile. Human readable date/time display options, timezone maps and timezone descriptions have also been added.
Online Help
The FAQ from phpBB 2.0.x has been migrated to an Online Help system which Blocks and Modules can dynamically insert help pages in to via Hooks.
Avatars
Avatars have been enhanced such that remote avatars are checked for size and dimension restrictions, this checking is highly optimized.
Gravatar support has also been added.
And so much more...
This list above is far from conclusive, it just gives an insight to where some of the improvements or changes have been made to the core. There are many, many others and do not forget there are nearly twenty Blocks and Modules available for R3-born which further extend its capabilities