To use Amfphp, download it here and then install it on your web server online or on your computer (local). Your server must run PHP 5.1 or more.
Your server should be configured so that making requests to a folder defaults to index.php, because the documentation and examples assume this. Otherwise you must direct your requests to <unzipped>/Amfphp/index.php
To install Amfphp locally on your development computer, you need a server which is capable to run on your operating system.
For information, there are several web servers that you can download for free.
If you run windows, we advise wamp. http://www.wampserver.com/
If you run linux, you probably have a server already available, check your documentation.
If you run osx, there’s a server included that you can use if you’re ok with messing with the configuration. If you’d rather just install something and have it work, there’s mamp: http://www.mamp.info/
Once you have a PHP capable server up and running, just unzip Amfphp in it.
Just check that your server supports PHP 5.1 or more. Then unzip Amfphp, and upload the Amfphp folder. The other folders and files contained in the zip are not needed for production use. You can however upload the BackOffice folder next to the Amfphp folder if you want it online.
Once you have Amfphp installed on your server, read getting started.