Throughout the worlds it is estimated less than 1% of all half elves live in half-elven communities. These communities tend to be small, averaging 100-1000 members.  They tend to work together, feeling that they cannot trust anyone except other half-elves.  Some of these communities accept other half-breeds, such as half-orc, half-ogres, half-dwarves, and the rare half-dragon.  Although they are welcome, they are rarely given positions of authority.  

In Fearun moderately large numbers of half elves can be found in Cormyr, the Dalelands, the High Forest and the Silver Marches but it is only in the Yuirwood that they have established a large community. Half elves in the other areas mentioned are either scattered throughout other mixed towns, or they live in smaller towns of a couple of thousand at most.

Although the types of societies are varied, there are a few common ones. 

Council:  These half-elves choose or appoint a council elder or members to make the important decisions of their lives.  Council leaders are usually older and wiser than the rest of the community.  These societies tend to be Good or Neutral in alignment. 
 

Outlaw:  This type of society is composed of outlaws.  They can be either true criminals or accused criminals.  Either way, they do not trust one another.  They are together for the protection of a large group and that is it.  A few rare ones actually try to impose order. These communities are often Neutral to Evil. 

Nomadic: This is rather common among half-elves.  They feel a kinship with one another and enjoy interacting with the rest of the world.  Some feel this is the only way to be accepted.  These communities can be of any alignment, but tend to be Neutral. 

Confederacy: This society is confusing for most non-half-breeds.  These half-elves try to represent each of the subraces with a council that has members of each subrace present.  Sometimes this seems to be the best type, except each council member gets one vote for every half-elf of the same stock.  This can cause problems with the races that are not represented well. 

Theocracy: There are some societies that feel that their god will carry them through tough times.  A common example of this is the priesthood of Beleghir.  These clerics form strong societies that care about, not only themselves, but the other races that live near them. 

Militocracy: Some half-elves feel that mercenary is the way to go.  These societies train all their members on fighting techniques.  This is often with weapons, but can include magic use as well.  Their leader is often a mid to high level warrior or warrior/mage. 

This list is far from complete, and there are examples of magiocracies, autocracies, and even feudalism.  Of course, the type of society will depend largely on the subrace.