Hello! As i noticed with some of my IRL mates, they did not know that there existed UI's and Mods for HoN.
Here is some of my personal favorites (Credit to HoN Official Forums)
Check how to install inside the links!
HoN Modification Manager 1.0
Heroes of Newerth Forums
It helps you install your Mods + UI , and updates every patch!
BardUI
http://forums.heroesofnewerth.com/showthread.php?t=23709
A very good UI! Shows cooldowns, your party, buffs etc very clear! Also very manageable!
HiM's Sound Mods
http://forums.heroesofnewerth.com/showthread.php?t=38888
A very fun Mod! Replaces the sound of some heroes with phrases from famous characters/people, like Homer Simpson for Pebbles, or Cookie Monster for Devourer.
Will update with more soon!