What’s New in WordPress 3.0 for Developers?

This article is outdated, check out what’s new in WordPress 4.6 here.

WordPress version 3.0 was released at the end of last week. It’s a little later than the intended May 1 release date, but WordPress is one of the most popular blogging and content management systems on the planet, so it was better to be late than cause issues for thousands of websites.

The update is the result of six months’ work by 218 dedicated contributors, culminating in 1,217 bug fixes and feature enhancements. So what can you expect from WordPress 3.0?

New Installer

WordPress has always been easy to install but it’s become even simpler. Few administrators will have to fiddle with the wp-config.php configuration file: all the MySQL settings can be specified within the installer panels now.

The new installer also allows you to specify the administrator ID and password. I suspect few people ever bothered to change it from the default “admin” in previous versions, so the facility to create your own ID will aid security.

New Interface

The WordPress 3.0 administration panels have received a polish. It’s hardly a radical change from version 2, but it’s lighter and feels slicker.

WordPress administration screen

There are few obvious changes to the interface until you reach the Appearance section.

New Default Theme

RIP Kubrick: you’ve served us well and many websites use you to this day. Kubrick has been replaced by “Twenty Ten,” a new theme that has built-in support for child themes, background alterations, header customization, and drop-down menus.

WordPress Twenty Ten theme

The theme’s look and widgets can be customized within the administration panel, so I expect many people will never venture beyond the Twenty Ten theme. For those that do, there’s a new “Install Themes” tab that allows you to search for templates by color, type, and features.

WordPress Multi-user

WordPress MU was a fork that allowed hundreds of blogs to run from a single installation; it has now been merged with the main version 3.0 application. It’s disabled by default, but can be switched on by adding the following line to your wp-config.php file:


define('WP_ALLOW_MULTISITE', true);

This could be the most important feature for web developers: you can create a number of websites using just one installation of WordPress. Updates are easier and hosting space is drastically reduced.

Custom Post Types

Pages and Posts were available in previous versions of WordPress:

  • Pages were normally used for static content such as About Us or Contact Us pages.
  • Posts would commonly be used for date-stamped news, articles, or blog posts.

WordPress 3.0 supports custom post types. For example, you could have a Product type that’s specifically used for items sold on your website. Product pages can then be treated separately; for example, have their own menu or search box.

Custom post types are configured using PHP rather than within the administration panels. Watch out for a full tutorial on SitePoint shortly.

Other Features

Where do I start? I suggest you visit the WordPress 3.0 Codex page for a comprehensive list.

Should you upgrade now?

I have no hesitation in recommending WordPress 3.0 for a new installation. But what if you’re upgrading from WordPress 2.x?

I’ve rarely experienced problems with the WordPress automated upgrade; it’s a quick one-click process that just works. However, my first attempt failed abysmally and I was left with a broken site. You should note that this was a test installation of 2.8.6 with lots of dodgy code and plugins, but you need to be wary: some themes and plugins are certain to break.

I would recommend updating a local test version of your site before attempting to upgrade the live server. Remember to back up your files and MySQL database, and you can’t go wrong.

If past experience is anything to go by, the WordPress team will almost certainly release 3.0.1 within a few weeks. If you’re especially nervous, you might be advised to wait a little longer …

Have you upgraded to WordPress 3.0? Did you experience any problems?