Windows
====================

For PHP4 use windows\php4\php_amf.dll and copy into ext folder of PHP
For PHP5 use windows\php5\php_amf.dll and copy into ext folder of PHP

Then update the php.ini with the line

extension=php_amf.dll


Linux/Others
====================

Build from sources and copy the amf.so library into the
ext folder of PHP (typically /usr/lib/php/modules). 
The update php.ini under /etc

extension=amf.so