Radar

From Secondhand Lands

With the radar overlay, you can spot critters, players, NPC's and usable objects all around you.

NPC's, critters and players will show up as a triangle, where the pointy end is the way they are facing. The colors of the triangle gives you a hint about what kind of entity you're seeing:
Red - hostile enemy (Aggressive critter or a player you are engaged in fight with)
Yellow - potential enemy (non-aggressive monster, or a juiced player of another faction)
Blue - a player that is neutral to you.
Green - a player in same guild as you
Pink - a GameMaster

Other symbols:
O - a circle on the radar represents a usable object. Sometimes quest related but also turds and water resources.
[] - a square on the radar represents a resource you can harvest or dig. You will only see resources relevant to your race.