This file format is available on GitHub for Unity users: īut for Unity users it's a bit complicated for an average user to compile it and can be unstable. The Khonos Group gives also informations about this file format:

Godot 3.0 uses it by default and explain why it should be the industry standard and the issues with FBX: GlTF + separated textures: the maps are exported separately but they are still appended automatically to your material(s) GlTF embedded: includes everything but it is a text file

Glb: the most interesting, this is the binary version, it is lightweight and directly readable by the GPU, it includes your PBR node materials, textures, LODs, animations GlTF or glb in his binary version is in his version 2.0 a new open source file format that allow you to export your game asset with his lods and animations like the FBX, but it has also the advantage of being open sourced so it can be easily implemented, it supports the Disney's Principled PBR and it be packed with your textures and materials and will automatically append and plug your textures, so you will get the exact same result across all applications.