The Witling
Appearance
The Witling is a 1976 science fiction novel by Vernor Vinge, about a planet populated by a race of nearly-human aliens who have the ability to teleport with their minds. This ability varies from person to person: those without the talent at all are called witlings and are the lowest class of person in the planet's primitive societies.
Two human explorers from a nearby colonized world become trapped on the planet, and struggle to find help from various powerful factions that wish to exploit the relatively advanced technology the humans brought with them.
The slower-than-light human colonization that serves as a backdrop for the setting is similar in description to the Slow Zone colonization in Vinge's 1999 novel A Deepness in the Sky.