The Makers of Light, Darkness, and Everything are, presumably, a group of Immortal Beings who have existed since before the beginning of the Universe, and the closest thing in The Good Place's universe that can be considered "God-like".
Creations other than Light and Darkness[]
The Makers of Light, Darkness, and Everything were the confirmed creators of Janets, as specified in the manual. It's unclear if they're responsible for all variations of Janet or just a core template version, or if they created all 25 generations of Janet or just the first generation.
The Makers of Light, Darkness, and Everything, may have invented The Afterlife as a way to punish and reward humans, although this has been neither confirmed nor denied.
Known Individuals[]
No Maker of Light, Darkness, and Everything has been confirmed to be seen.
Presumably, at least one of the Makers of Light, Darkness, and Everything is also a maker of manuals, since Janets come with a manual.
However, Judge Gen may be one of them, as she states that the only thing in existence when she was born was hydrogen. Additionally, Janet also confirmed that Judge Gen was around when light was created.
Neil may also be one of these Makers, as he is the Head of the Accounting Department, and either did or did not have a role in creating it.
Not all Immortal Beings are Makers of Light, Darkness, and Everything; as the Janet Manual presumes that Architects are not Makers of Light, Darkness, and Everything.