Accelerating the international use of climate mitigation technologies is key if effortsto curb climate change are to succeed, especially in developing countries, where weakdomestic technological innovation systems constrain the uptake of climate change mitigationtechnologies. Several intergovernmental agencies have set up specific programmes to supportthe diffusion of climate mitigation technologies. Using a simplified technological innovationsystem-based framework, this paper aims to systematically review these programmes, with thedual aim of assessing their collective success in promoting technological innovation, andidentifying opportunities for the newly formed UNFCCC Technology Mechanism. We concludethat, while all programmes reviewed have promoted technology transfer, they have givenlimited attention to innovation capabilities with users, government and universities. Functionsthat could be further developed include knowledge development, legitimation and marketformation. These could be focal areas for the UNFCCC Technology Mechanism. We recommendthat, in future programmes, part of the funding is dedicated to programmes doingresearch and development as well as capability development.