mlmac uses mlnet (aka mldonkey) to connect to different networks including, but not limited to, eDonkey/eMule and Overnet. The power of these networks (and some others) relies in the fact that users share files while downloading them and thus allow people to dowload a file from a large number of sources even if most of them haven't finished downloading it. So mlnet will automatically share all the files that you are downloading. Btw, someone who wants to download files on a P2P network without sharing hasn't understood P2P. Read the doc, FAQs and forums (such as http://www.macdk.com) to learn more.