[snowcorn]

We have:

"D" the programming language [0]

"D" the data language specification [1]

"D" the programming language for DTrace [2]

"D3" the javascript library [3]

"D4" library/tool for Declarative Data-Driven Documents[4]

"D4" implementation[5] of the data language specification[1]

Overall, I think "D2" is objectively the best choice here. We have at least three "D"s, two "D4"s, and one "D3", so it makes sense to put it in as "D2". I certainly wouldn't want another "D" or, heaven forbid, a "D5".

[0]: https://en.wikipedia.org/wiki/D_(programming_language)

[1]: https://en.wikipedia.org/wiki/D_(data_language_specification...

[2]: https://en.wikipedia.org/wiki/DTrace#Description

[3]: https://d3js.org/

[4]: https://github.com/joelburget/d4

[5]: https://en.wikipedia.org/wiki/Dataphor#Languages

[tomwojcik]

As a gamer, after reading just "D2" my brain immediately assumed it's about Diablo 2 Resurrected.

[Ancapistani]

I thought of the D-2 extract on Reserve in Escape from Tarkov.

[gpm]

"D1" CloudFlare's database thing