Of course @digitalgyoza!
The blog utilizes software called Utterances. It cleverly uses Github issues as the backend to host a lightweight Markdown based commenting system. Here is an example of Utterances in action from that blog.
I included how Robert Xu, the owner of the blog, puts it in his Custom Javascript on Write.as on this list here. As you will see, this is part of a bigger project to make the Custom Javascript and CSS on Write.as blogs more transparent for everyone. So please feel free to contribute your own blog or others to the list!
And thanks for your kind words! I am in awe of anyone who takes on writing a novel!. Hope to hear more about [D]rifter soon!