Wikipedia
The valknut ( Old Norse valr, "slain warriors" and knut, "knot") is a symbol consisting of three interlocked triangles, and appears on various Germanic objects. A number of theories have been proposed for its significance.
The name valknut is an unattested modern invention used to describe the symbol, and was not used contemporaneously with the symbol. The valknut has been compared to the three-horned symbol found on the 9th-century Snoldelev Stone, and may be related to it.
In Norwegian (Bokmål) the term valknute is used for a polygon with a loop on each of its corners. In the English language the looped four-cornered symbol is called Saint John's Arms.
Valknut is a program that uses the Direct Connect protocol. It is compatible with other DC clients, such as the original DC from Neomodus, DC++ and derivatives. Valknut also interoperates with all common DC hub software.
Valknut was originally written by Mathias Küster and is licensed under the terms of the GNU General Public License (GPL). It is written in C++ and uses the cross-platform Qt library for its GUI. Valknut compiles and runs on Linux, FreeBSD, Mac OS X, Microsoft Windows, and OS/2 - eComStation.
Originally, Valknut was called DCGUI, which was similar to the name of another Linux DC client. It was then renamed to dcgui-qt to avoid confusion. However, trademark problems relating to the use of 'Qt' in the name forced another name change, to Valknut.
Following the release of Valknut 0.3.7, Mathias Küster stopped working on Valknut. Edward Sheldrake then moved the code into the wxDCGUI project, where work is underway to add additional features, as well as to port Valknut's Qt3 user interface to Qt4 and eventually to wxWidgets. In May 2008 the first Qt4 version was released.
During startup, the graphics of the splash screen show a Valknut.