This is an updated version of one of my favorite addons, originally by John "Cryect" Rittenhouse. The addon was later updated for TBC and the new Lua 5.1, but fell apart when the new combat log was implemented. I've updated it to function correctly with the new combat log.
CombatGraph tracks damage and/or healing from and/or to specified targets and displays the data it collects on a realtime graph. This is useful for, among other things, DPS who want an easy to interpret display of how much damage they are putting out and healers who want to see how the tank is taking damage.
Slash command: /cg
From Cryect's original readme:
A customizable realtime DPS/HPS graph. If you've ever wanted to visually see how your DPS is over time or just don't feel like looking up on top of Ragnaros's head or reading your combat to see your damage now you can graphically see it.
This mod was created when I was trying to come up with some ideas for how could improve my healing by delivering information about the current fight to me better. So I came up with the idea of tracking the current DPS on the main tank in a graphical form. But first before doing that I figured I should make a mod that tracks the DPS you do in a graph and this is the result of that. Its somewhat loosely based on the mod called Gram which I used as a base since this is the first UI mod I've ever done but its almost completely rewritten from scratch and a lot better performing (http://www.curse-gaming.com/mod.php?addid=349).
All there is to it is a draggable frame that has a graph of your DPS over time and states your current average DPS. Your burst DPS is determined through a running exponetial falloff sum of damage and the falloff rate can be adjusted. The graph is displayed using gradients because well they look cool and are fully adjustable to whatever colors you want for the top and bottom (default is black on the bottom and red on top).