O Pioneer! by Frederik Pohl

The overcrowded Earth isn't room enough for Evesham Giyt, a solitary and brilliant computer hacker who yearns for the long-gone frontiers of the past. Chasing stories of unspoiled beauty and endless possibility, he takes a leap across the stars to the rugged colony world of Tupelo and soon finds himself a respected member of the community and mayor of the colony's human population.

Humanity isn't the first race to colonize Tupelo: as mayor, Giyt is part of a council of races trying to peacefully coexist despite wildly disparate cultures and traditions. But as Giyt learns to like his alien neighbors, he begins to realize that his fellow humans may have other plans for Tupelo, plans that don't include peace but do include lots of dead aliens. It will be up to Giyt to crack the human conspiracy and carve out a future for all of Tupelo...before it gets him killed!