The technology of fiber positioning robots has been evolving in the recent years and currently lacks of a comprehensive view. This thesis aims at filling this gap. Fiber positioning robots are analyzed under different aspects: a theoretical framework, design guidelines and a discussion on the limits of the technology are provided. Furthermore, a detailed description of two robots that we have implemented is given, together with the related performance results. The theoretical framework and the design guidelines can be a tool for future work on fiber positioners. The smallest robot we have developed is at the technological frontier and represents a novelty in the state of the art.