Earlier this year, the Joomla development team announced that support for Joomla 1.5 will cease in April 2012.

Joomla 1.5 websites will, of course, still operate after this date but security vulnerability fixes may no longer be available.

The next long term release version of Joomla, called "Joomla 2.5" will be available from January 2012.

Advice for Existing Joomla 1.5 Users

Plan to upgrade your Joomla 1.5 website to Joomla 2.5 between January 2012 and April 2012. Note that extensions from older Joomla releases usually have to be rewritten for the new Joomla releases. There are no guarantees that new versions of the extensions you are currently using will be available when you need them. You may need to check with the developers about their plans or check for alternative extensions that suit your needs.

The degree of difficulty in upgrading your Joomla 1.5 website to Joomla 2.5 will depend on a number of factors including the third party extensions are installed, and the content that needs to be brought across.

New Website Strategy

Joomla 1.7 was released in July 2011 and many extension developers have now released updated versions of their extensions. Unless there is a key extension you need for your website that is not yet available for Joomla 1.7, then I advise that new websites should now be built with Joomla 1.7. This will likely provide an easier upgrade path to Joomla 2.5 when it becomes available in January 2012.

More Information

There is an excellent infographic of the Joomla versions and support dates in the August 2011 issue of the Joomla Magazine.

The official Joomla Development Status is on the Joomla Developer Network website.

Official upgrade advice can be found on the Joomla Community website.