Ok, you are about to code a great new application in PHP, that will be downloaded millions of times and be installed on shared servers all over the world. Being the cutting edge developer you are, you will use all the latest PHP features like closures and namespaces. What is stopping you from world domination?
I had occasion to set up a dev box to test a new web application against different php versions, so I thought I would share the steps. This setup is for one PHP version at a time, and I have documented for 2 versions, but more can be done if required. Also I have used PHP4 and 5, but it could be multiple versions of PHP5, such as a beta version of 5.3. This setup was done using Apache2 on Windows.
PHP 4.4.9 has been released. This is to be the last release on the 4.4 line. This release is a combination of security enhancements and fixes. And all just before 8/8/08.
PHP6 is still on the distant horizon, but closer is 5.3 which had a first alpha released a few days ago.
It has been announced that PHP4 support is to cease with only critical support fixes to be made. The details are that new releases on the PHP 4 line will cease at the end of 2007, and security fixes may be made available until August 8, 2008. They encourage all users to upgrade to PHP5.
PHP6 is on the horizon but no definite timeframe is given.