Commercial distributors can simply ship disks or archives containing only their additional modules, without the need to create fixed and solid PHP binaries that don 't allow other modules to be bound to them.
Third parties might consider using the extension tag in php.ini to create additional external modules to PHP. These external modules are completely detached from the main package, which is a very handy feature in commercial environments. Commercial distributors can simply ship disks or archives containing only their additional modules, without the need to create fixed and solid PHP binaries that don't allow other modules to be bound to them.