The title given to this article is incorrect due to technical limitations. The correct title is BCDC++.
BCDC++ is a computer program to download files and make P2P communication. It is a modified version of the famous DC++. It allows upload/download limiting, lua scripting, and many other features. The lua scripting is extremely powerful, doing things like setting custom colors, and ignoring users.
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++.
As of 2002, DC++ was still not accepted into some hubs because it was understood that the number of slots is shared by all the hubs that the client is connected to.