This document reviews jatropha and the potential it presents for the world's poor as a business opportunity and access to renewable energy sources. Jatropha is an oil-bearing crop, which produces a seed that can be processed into a "clean" biodiesel. In addition to its ability to grow on degraded and marginal lands, this crop also grows in dry climates, making its cultivation even more appealing. Growing energy crops such as jatropha could enable some smallholder farmers, producers, and processors to cope with pressures on their livelihoods. The report covers the production of jatropha, its applications, policy solutions, and case studies in South Asia and Sub-Saharan Africa.