Another Heaven, Another Earth — H.M. Hoover

Of the original population that colonized the planet Xilan five centuries before, a mere handful of descendants remain, including Gareth. Despite disease, starvation, and hardship, they survived. Much, including their technology, was lost as they learned to adapt to Xilan's primitive conditions. When a new expedition from Earth lands with bold plans to re-colonize Xilan, however, a clash between the “primitives” and their “rescuers” becomes inevitable.

Gareth must make a decision: accept the new ways and risk losing their identity, or cling to the past...and risk extinction.