Excellent mechanical and electrical properties of multifilamentary NbTi have made it the conductor of choice in superconducting accelerators starting from the Tevatron. However, the LHC operating field of 8.33 T is close to limit for NbTi technology. In order to advance to higher fields, a superconductor with higher upper critical field is needed. At present, Nb3Sn is the most suitable material in terms of properties, availability, and cost. In contrast to NbTi, Nb3Sn is brittle and strain sensitive. Magnet R&D programs are underway worldwide to develop technologies that can take advantage of Nb3Sn properties while coping with the associated challenges. Status and accomplishments of the different programs are reviewed in the context of the requirements of next-generation accelerator facilities and possible upgrades to present ones.