It’s a modern C++ tool that can read and understand XVD (Xbox Virtual Disk) files. These are the files used by the Xbox One, Xbox Series and Windows PC family of consoles. It’s a format that describes a virtual disk (similar to VHD) specially tailored to carry game files and Xbox operating system files. It is used by the Xbox One hypervisor, the Xbox Series hypervisor, and the Xbox One/Series Operating Systems and bootloaders. The project is still more of a proof of concept, it lacks most useful features.
There are some challenges for newcomers, you can find them here
Because it’s a lightweight and well-known language with a nice set of standard libraries for PC programming. It also supports object oriented programming, which XanaduXVD uses.