A few days ago I had to create an architectural diagram for my client. I found d2lang and liked its visual style a lot. Then I quickly found your blog entry/tutorial thanks to an old HN post which allowed me to complete the diagram in about 1 hour. Thanks a ton for having it published, I know that I will be a frequent user of d2lang now and that is also thanks to your article which contains all important instructions for a reader to successfully get started with d2lang.
While you're here: while skimming I noticed under the headline Connections one of the samples has the wrong label. Instead of `Gordon <-> Mia: ->` it should be `Gordon <-> Mia: <->`