If the project leaders and users of your favorite content management system are still debating when they should drop PHP 4 support, it looks like the PHP development team has helped make that decision for them. PHP.net just announced the End of Life for PHP 4. Starting in 2008, only security updates on a case-by-case basis will be provided...and PHP 4 is dead in August 2008.
Today it is exactly three years ago since PHP 5 has been released. In those three years it has seen many improvements over PHP 4. PHP 5 is fast, stable & production-ready and as PHP 6 is on the way, PHP 4 will be discontinued.
The PHP development team hereby announces that support for PHP 4 will continue until the end of this year only. After 2007-12-31 there will be no more releases of PHP 4.4. We will continue to make critical security fixes available on a case-by-case basis until 2008-08-08. Please use the rest of this year to make your application suitable to run on PHP 5.
More information available at PHP.net. So no more excuses...if you're still running PHP 4 there is no time better time than the present to check out PHP 5.