A few days ago The PHP group announced they will discontinue PHP4 development. After New Year there will be no more releases of PHP 4.4. They’ll continue to make critical security fixes available on a case-by-case basis though, until August 2008.

The PHP group also urges everyone to use the rest of this year to make their applications suitable to run on PHP 5. And with PHP6 just around the corner this might not be a minute to late…

For documentation on migration for PHP 4 to PHP 5, you could use the official PHP migration guide, or you could follow my tutorial on how to install PHP5 on Windows.

In case you are running a fresh install you might also be interested in some of my other installation tutorials about Apache2 (web server) and MySQL5 (database).