As of 2008[update], DC++ had around 90% market share of the Direct Connect community.
DC++ is a free and 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 that it has no adware of any kind, unlike NMDC.
Many other clients exist for the Direct Connect network, and most of these are DC++ "mods": modified versions of DC++, based on DC++'s source code. A partial list of DC++ mods is given below. Some of these clients were developed for specialized communities (e.g. music-sharing communities), or in order to support specific experimental features, or perhaps features that have been rejected from inclusion in DC++ itself. An example of an experimental feature is hashing, which was initially implemented in BCDC++ and later adopted by DC++.
An advantage of the free and open-source nature of DC++ is that several mods have been released which add features to the original client.
Many users send patches to DC++ which are included in future releases, but some features are rejected by the developer. Stated reasons for rejecting a patch are because they are coded poorly, or that the feature is frivolous, abusable or overly specialized, and does not belong in the main client. Examples include: upload bandwidth limiting (many users feel that upload bandwidth limiting is a form of cheating, while other users not using a full-duplex network connection can only achieve reasonable download speeds by limiting uploads), colorized chat, specialized operator functions (e.g. client/share checking).
The developers of some forks contribute features and bug-fixes back upstream to DC++.