WinMX
WinMX is a peer-to-peer file sharing program authored by Frontcode Technologies. WinMX began its life as an OpenNap client capable of connecting to several servers simultaneously, although Frontcode later , starting with WinMX 2, created a proprietary protocol, termed WinMX Peer Network Protocol (WPNP). WPNP version 2 was phased out as WinMX 3.0 and its WPNP version 3 protocol came into existence. Frontcode operates several cache servers to aid WPNP network operation.
Lopster used to have WPNP 2 support, although it was locked out with the arrival of WPNP 3.
WinMX was very popular in Japan due to its ability to handle 2 byte characters. By 2001 it was the de facto P2P application in Japan. However, WinMX's Japanese popularity dropped sharply with the arrest of several users, and resulted in the development of a semi-secure, encrypted, serverless application called WinNY (N comes after M, Y comes after X).