PHP 5.3.0 is only in its first alpha release. But, if you run PHP in Microsoft Windows, you should talk a look at…
Release Notes for Windows Binaries (for PHP 5.3.0)
Here are the important changes:
– Support for Windows versions prior to Windows 2000 have been dropped. If you run PHP on Windows 98, 98SE, ME, and NT and plan to upgrade PHP to 5.3.0, start your Windows upgrade planning now.
– Up until now, PHP for Windows has been compiled using Visual C++ 6 (VC6) which was released in 1998 (no kidding). There will be two binary builds available for Windows for the 5.3 release. If you use 3rd party extensions or the Apache httpd server, you need to use the build compiled with VC6. Otherwise, you can use the version compiled with VC9. Future versions of PHP compiled binaries will only be released as compiled with VC9.
– 64-bit binaries will be provided on an experimental basis. They should not be used in production environments. The release notes do not discuss running the 32-bit binaries in a 64-bit environment (Windows Server 2008).