MET is the extension of files mainly related to P2P network file sharing software called eMule. MET files are used by the program to store lists of servers with which this client exchanges data. In addition, MET files contain links to resources that are to be downloaded or are in the process of being downloaded. This allows the download to resume after you exit the program and restart it at a later time.

eMule is a free peer-to-peer client based on the eDonkey and Kad communication networks. The program is no longer being developed.