I did a bit of prowling around the DK class AddOns on Curse, CurseForge and WoWAce and WoWUI (I know this mod is not on WoWI. On the curse site, I found this mod:
Void Runes:
http://wow.curse.com/downloads/wow-a...voidrunes.aspx
The last three lines in the description (there is no screenshot, friggen Curse does not require them, yet) caught my eye:
* Kassay - Created the
triangle texture
* Nathyrra - Inspiration and testing
*
DKI - Rune icons
- Emphasis by me.
The Runes in that screenshot you posted are the DKI Runes (I them quite well since I hang out at DeathKnight.info) and thus far I have found only two mods that use those Runes, this mod and Deathknight.info's own Rune mod.