What is Joomla 2.5?

The new major release of Joomla has been named version 2.5. This follows a very confusing path from 1.0, to 1.5, to 1.6 and then 1.7! The important thing to note is that versions 1.6 onwards represent an important benchmark in the Joomla development roadmap, and many third party extensions that worked with Joomla 1.5 won't work with 1.6+. And what's really important is that Joomla 2.5 marks the beginning of a new era for Joomla, and the beginning of the end for Joomla 1.5, which will be no longer supported after April 2012.

Joomla 2.5 is a mature, long term release of the Joomla platform that has been completely redesigned from the ground up. Major new features include unlimited nested content categories, and access control to site content and functionality through custom user groups. Although the admin interface looks similar to previous versions, under the bonnet everything is shiny and new, and built with the developer in mind. For custom built web application development, Joomla 2.5 is simply unsurpassed by any other open source platform, and rivals most proprietary solutions as well. The price of this leap forward is backward compatibility. Much like when Apple moved to OSX and left their customers having to purchase all new software, moving from Joomla 1.5 to Joomla 2.5 is a big migration, and will involve conversion of templates, components and plugins as well as all content. Depending on the complexity of your website, this could be a very involved process.

If you are on Joomla 1.6 or later, the move to Joomla 2.5 is very straight forward, similar to a standard minor upgrade patch.