An important feature of a &mgr;-storage ring &ngr;-source is that it can be extended to the possibility of a future high-energy muon collider. The neutrino source provides a useful physics device that initiates key technologies required for future&mgr;+–&mgr;−colliders but with much less demanding parameter requirements. These technologies include high-intensity &mgr;-production, &mgr;-capture, &mgr;-cooling, &mgr;-acceleration and multi-turn &mgr; storage rings.&mgr;+–&mgr;−colliders require a similar number of muons, but they require that the muons be cooled to a much smaller phase space and formed into a small number of bunches, and both positive and negative bunches must be simultaneously captured. These differences are discussed, and the extension of the &ngr;-source to&mgr;+–&mgr;−collider specifications is described. ©2000 American Institute of Physics.