Maize is one of the most important food crops in the world. In 2016, global acreage of maize was 188 million ha, of which 36% (68 million ha) were in developing and low-income countries (FAOSTAT, 2018). Together with rice and wheat, it provides at least 30% of the food calories to more than 4.5 billion people in the developing world (Shiferaw et al., 2011). The role of maize to ensure rural food security is even higher in some of the least developed countries of sub Saharan Africa. For example, over 55% of the daily calorie intake of Zambian households is derived from maize alone (Khonje et al., 2015). However, maize is not only a food crop for humans. Demand of maize has increased as feed and fodder for livestock production, driven largely by the rapid economic growth in Asia and Latin America (Hellin et al., 2015). It also has significant industrial importance as a raw material for bioethanol production, also in developing countries, alongside other crops. Meeting this increasing food-feed-energy demand is one of the major challenges of maize production sectors across the developing world, which are constrained by natural resource depletion and degradation, input scarcity, climate change, and persisting poverty among the producers. Shortfalls in maize supplies and resulting increases in the food prices have grave consequences for developing countries as food will be less affordable for millions of poor consumers (Shiferaw et al., 2011). Although the maize area expansion is unprecedented in many parts of the global South, area expansion will not be a sustainable solution to meet the market demand. Increases in cultivated area often comes with an environmental cost of land degradation and biodiversity loss. There have been many compelling success stories with respect to productivity enhancement of maize, with the increased adoption of new seeds and associated technologies. This research-for-development (R4D) interventions could possibly have significant livelihood implications for both maize farmers and consumers. The CGIAR Research Program on Maize (CRP MAIZE or simply MAIZE) is part of a concerted effort of to implement a new, results-oriented strategy in maize agri-food systems, exploiting the potential of international agricultural R4D fully to enhance global food security and environmental sustainability. Two CGIAR centers – the International Maize and Wheat Improvement Center (CIMMYT) and the International Institute for Tropical Agriculture (IITA) – have lead this CRP since late 2011. The shared challenge of the Program is to “double productivity and significantly increase the incomes and livelihood opportunities from more productive, resilient and sustainable maize-based farming systems on essentially the same land area – while contending with climate change and increasing costs of fertilizer, water, and labor” (CRP MAIZE, 2016). Through MAIZE-driven R4D, targeted crop productivity growth of 20% by 2020 and 50% by 2050 in 60 major maize producing countries should contribute to food/feed access and stable prices for over 900 million poor maize consumers. Sustainable intensification of maize production and stabilization of the total maize area at about 120 million hectares in developing countries is the second objective of MAIZE. The other impact targets are to (a) reduce the frequency of production shortfalls and price volatility in areas and countries where the probability of crop failure in maize-based farming systems is high, (b) diversify maize based farming systems and enhance their productivity and sustainability, dealing specifically with the systems with the highest poverty concentrations, (c) ensure that higher rates of maize yield growth are sustained in the face of climate change, worsening water scarcity, and rising fertilizer prices, and (d) increase opportunities for diverse market participation. Research programs and projects built around these objectives are expected to target two groups of farmers that occupy approximately 64% of all maize area in the Global South and are home to 1.2 billion of the poor and 126 million malnourished children.