A file with the extension .AHL is a configuration file associated with 'eMule' a free peer-to-peer file sharing application for Microsoft Windows.

File sharing refers to the providing and receiving of digital files over a network, usually following the peer-to-peer (P2P) model, where the files are stored on and served by personal computers of the users. Most people who engage in file sharing on the Internet both provide (upload) files and receive files (download).