The DC++ distribution has three files:
A Windows Installer that sets up DC++ for immediate usage (into your Program Files folder, with shortcuts and user profile support).
This file is of the form DCPlusPlus-###.exe.
A binary archive that can be unzipped anywhere and usable right away (portable version, without any shortcuts or registry information created).
This file is of the form DCPlusPlus-###.zip.
An archive with the source code that was used for compiling and creating the executable distributed in the other packages; targeted at experienced programmers.
This file is of the form DCPlusPlus-###-src.zip.