For End Users: Overview

APML allows you to share your own personal Attention Profile in much the same way that OPML allows the exchange of reading lists between News Readers. The idea is to compress all forms of Attention Data into a portable file format containing a description of your ranked interests.

From CleverClogs

...Attention profiles are consolidated, structured descriptions of people's interests and dislikes. The information about your interests and how much each means to you (ranking) is stored in a way so that computers and web-based services can easily read it, interpret it, process it and pass it on should you request and permit them to do so.

Getting an APML file
A growing number of services support APML export. As you use them, they will update your APML file and allow you to export it.

Using an APML file
A growing number of services support APML import. They allow you to upload your APML file to get an instant understanding of your interests.