On 18^th December 2009, a week before Christmas, WordPress version 2.9 was released to the public. This version of WordPress blogging software is named “Carmen” and comes with a list of new features, some major enhancements and bug fixes from its previous version. The requirement for the database is MySQL 4.1.2 or above.

Wordpress version 2.9 provides the smoothest and comfortable way to write articles because of major and significant user features are introduced as well as more subtle improvements have been loaded in this version.

The great new features from a user point of view are,
1. Global undo or “Trash” feature

It acts like a recycle bin in most of the modern operating systems. It allows users to temporary delete posts, pages or comments to the “trash” and users can restore back the posts, pages or comments from the “trash”. So, users will never accidentally delete a post, page or comment. The items inside the “trash” are keeping for 30 days by default whereas users can defined the number of days at wp-config.php to hold the deleted items in the “trash”. For example,
define('EMPTY_TRASH_DAYS', 7);
Note: This feature can be disabled by add the following code at wp-config.php
define('EMPTY_TRASH_DAYS', 0);

2. Built-in Image Editor

This is one of the interesting feature in WordPress version 2.9. Users can perform image cropping, rotation, flipping, resize and set the aspect ratio instantly from the editor.

3. Batch plugin update and compatibility checking

It allows users to upgrade 10 plugins at once, so they no need to multiple clicks for each one for the plugins’ upgrade. It is using the new compatibility data from the plugins directory to give the users a better idea of whether their plugins are compatible with the new releases of the WordPress.

4. Post image feature

Users can upload a post thumbnail and the image can be in various sizes. It is the image-based representation of a post to make the readers have a rough idea on your post by the first look of the thumbnail. Normally the image itself is directly tied to the post.

5. Easier video embeds – This feature allows users to just paste a URL on its own line and have turn in into the proper embed code. oEmbed supports for youTube, Daily Motion, Flickr, Hulu, Google Video and more.

6. Better SEO with “rel=canonical” – It allows users to add a new tag to the page header that specifies the canonical path to the actual content to prevent duplicate contents that accessible through multiple URLs. This helps to increase the link popularity, well indexed in various search engines and so on. Source.

7. Automatic Database Repairing – Users can perform automatically database repair by define a code in the wp-config.php.
define('WP_ALLOW_REPAIR', true);

8. New Category Template – Sometimes, users had to use a query in the theme or a plugin to custom adjust the design or content for a specific category. WordPress version 2.9 has expanded the template hierarchy so users can easily customize their own template for a specific category with the help of the category’s slug. For example,

<?php
if ( is_category('special-category') ) {
/* You can output or include a CSS Stylesheet for the category Special Category, make it different layout presentation along with other categories. */
}
?>


9. Extend the User Contact Information


Wordpress version 2.9 allows developers to write a patch in functions.php to customize and filter the user contact fields. Users can also remove the existing fields. For example,

<?php
function additional_contactmethods( $contactmethods ) {
// Add Twitter
$contactmethods['twitter'] = 'Twitter';
//add Facebook
$contactmethods['facebook'] = 'Facebook';
return $contactmethods;
}
add_filter('user_contactmethods','additional_contactmethods', 10, 1);

// Remove Yahoo IM
unset($contactmethods['yim']);
?>

Users can display the field on the author page.

<a title="Facebook" href="<?php echo esc_url($current_author->facebook);?>">Find us at Facebook</a>


10. Upgraded TinyMCE editor (version 3.2.7 ) and Simplepie.

WordPress version 2.9 introduction video

There are more noticeable features in WordPress version 2.9. A full list of change log and features can be found in WordPress official website.