What does XDG stand for?

Solution 1:

From https://www.freedesktop.org/wiki/

freedesktop.org hosts the development of free and open source software, focused on interoperability and shared technology for open-source graphical and desktop systems. We do not ourselves produce a desktop, but we aim to help others to do so.

We also host discussion and development of specifications for interoperability. A full list is available at our specifications page.

These specifications mostly cover low-level desktop issues, such as identifying file types, launching applications, and exchanging data between applications and desktops. They are often called 'XDG' specifications, as an acronym for the Cross-Desktop Group.

So to answer my question, XDG stands for "Cross-Desktop Group", and it's a way to help with compatibility between systems.