If you play a DeathKnight regularly as I do, you know that Blizzard's rune display is insufficient for active play. ThreeRuneBars was created to solve this problem. It isn't just a new skin for your runes, it completely redesigns how you view which runes are available. Instead of six separate runes, TRB creates 3 bars that function much like the energy bar of a rogue, one for each type of rune. Regardless whether you use FrostRune1 or FrostRune2, you will see that your frost rune bar is half full. I find that this yields greater response time when deciding what ability to use next.