The Cloak of Darkness is a specification for an adventure game that has been created in numerous systems, with the purpose of giving prospective authors some idea of what is involved in each system.
IFWiki says of it:
This adventure is a tiny adventure designed to be easy to port to a given Authoring system. It is, if you will, the interactive fiction equivalent of “Hello, world!”
The Cloak of Darkness has its own web site that at one time kept up to date with IF authoring systems and their implementation of it.
Unfortunately it has not been updated in well over a decade, and apparently that is not about to change. Quest is on there, but a very early version, 3.5, which is very much a different system. Back then, Quest had two programs, one that was free, to play games on, and the QuestPro version, which you had to pay for, and could be used to create games. The file format was also completely different.
Modern Quest dates from August 2011, and the introduction of Quest 5, when it went open-source, free for everyone and XML-based.
I recently came across a thread on intfiction.org about the Cloak of Darkness (the first I had heard of it), and thought it would be interesting to do a modern version of it.
There is a problem with the concept behind The Cloak of Darkness. It is attempting to show how easy it is to create in each language, by showing the source code. But with Quest – and other systems too – you do not look at the source code. You would need to look at numerous windows and tabs (things that make authoring much easier, but make documenting authoring rather more trouble!).
So you can look at the source code for the Quest version, but really that does not tell you much. You need to understand the steps involved in creating it.
And so I present:
This is a new page in the Quest documentation that describes how to build a full version of Cloak of Darkness from scratch, explaining at each step not just how to do it, but why it was done that way. There are links to a working game, and you can download the source code and open it up in the desktop version to take a look too.
Text Adventures Blog 
Ah, most interesting…but not what I was expecting! With mention of ‘hello world’ for text adventures, I thought this would be demonstrating how easy it was to create the game in Quest. What’s presented, however, feels more like an advanced tutorial on how Quest games can be tuned to achieve a professional finish. That’s helpful, but it might also be useful to include the minimal game in the discussion as well.
DavyB
Yes, this is the advanced tutorial. There is already a basic tutorial here:
http://docs.textadventures.co.uk/quest/tutorial/
I tried to bring the game closer to basic Quest but ran into issues that seem to suggest possible improvements for the next Quest release. This is probably a topic for the Forum, however! It’s great to have a simple base game around which improvements can be discussed.