In this article, the use of the niche concept for explaining radical technical change is explored. Contributions of various strands of literatures are elaborated and systematized in a taxonomy. Radical change or technological discontinuity is defined as the establishment of a new sociotechnical regime. Sociotechnical regimes carry and store rules for how to produce, use and regulate specific technologies. They perform the task of genes and define the boundary between technological species. It is proposed that radical change is generated by four different evolutionary mechanisms and patterns: natural selection, punctuated equilibrium, market niche selection, and technological niche selection. In each pattern, a different type of niche is implicated in the change process. The difference between niches results from differentiating between two dimensions: (1) whether niches are internal or external to the prevailing sociotechnical regime; (2) whether rules for design and use of a specific technology are stable or unstable within the niche. © 2007 Springer-Verlag.