Running PHP 3 and PHP 4 concurrently

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 PHP3 and PHP4 to use APXS (--with-apxs) and the necessary link extensions (--enable-versioning). Otherwise, all standard installations instructions apply. For example:

$ ./configure \
  --with-apxs=/apache/bin/apxs \
  --enable-versioning \
  --with-mysql \