The "play after downloading" and "direct play online" for streaming media have an immeasurably vast difference on experience. However, streaming media websites providing online music or video play service have been facing two development difficulties: copyright and server performance. For the former, if they chose to buy the original copyright, the investment will be huge, and comes with too few resources and very slow update; if it was pirated, then that's always possible to be under surveillance and even shut down at any time. In the latter case, the more people visit, the worse the server performance will be, which means either they have to increase the hardware investment, or it's difficult to get further development.

eMule used to be the largest and most trusted free P2P file sharing client developed by Hendrik Breitkreuz from Germany. It was started in 2002 as an alternative of eDonkey2000 (AKA: eD2k) based on eDonkey Network, retained all advantages of eDonkey, added new functions and more friendly UI.

μTorrent (AKA: microTorrent or uTorrent, short for "µT" or "uT") is a freeware BitTorrent download client, written in C++. It is the most widely used BitTorrent client now, outside China (where XunLei is more popular and has the has the largest number of users in the world).