What is RuneMod??
RuneMod adds high detail graphics to Old School  Runecape.
It runs in the RuneLite client, as a plugin.

How does it work?
The Runemod plugin sends graphics data to a rendering application. This renderer can modify the graphics in all manner of ways.

Can Runemod cause account bans?
There have been no bans on Runemod.
Runemod is essentially an advanced overlay. It displays graphics over RuneLite without modifying runelite.