DC++ is an open-source, peer-to-peer file-sharing client that can be used to connect to the Direct Connect network. It is developed primarily by Jacek Sieka.
As of 2006, no official statistics exist to verify the proportion of DirectConnect users using DC++. However, it is generally believed to be the most extensively used by a large margin; administrators of popular public DirectConnect hubs generally agree that DC++ is the client used by a significant majority.
DC++ is an open-source alternative to the original client, NeoModus Direct Connect (NMDC). It connects to the same file-sharing network, and supports the same file-sharing protocol. One of the reasons commonly attributed to the aforementioned popularity of DC++ is the fact that it has no adware of any kind; NMDC on the other hand contains adware.