Recent operating systems provide the ability to perform
versioning and scoping. This features make it possible to let
PHP 3 and PHP 4 run as concurrent modules in one Apache server.
This feature is known to work on the following platforms:
To enable it, configure PHP 3 and PHP 4 to use APXS
(--with-apxs) and the necessary
link extensions (--enable-versioning).
Otherwise, all standard installations instructions apply. For example:
$ ./configure \