You can create a group with this script similar to group system in mmorpg games and the XP is shared between players, for example if a players kills a zombie, other members of the group also get the XP from the zombie.
Only group leader can invite players.
You can leave from the group with command. If the player that left is the leader his leader tag is passed to someone else in group.
If none is left in group, the group gets deleted automatically.
You can see the blips of player who are in your group.
Works with infinity