Recognizing the importance of immigrants to Greater Boston and the value of English classes and other supports to building an inclusive and welcoming community, the Boston Foundation and the Latino Legacy Fund commissioned a study that explores the "return on investment" (ROI) for teaching English to adults who are speakers of other languages. The result of that study is this report, comprising an analysis of the region's English for Speakers of Other Languages (ESOL) landscape that provides background and context for the in-depth case studies and ROI estimates that follow. The report identifies key demographic, socio-economic and policy factors that shape the context in which ESOL programs operate, and provide an overview of the ESOL system that highlights the funding sources and stakeholders who are the principal drivers of the system. The landscape analysis provides an assessment of the need for English language services and a snapshot of the current supply of ESOL services in Greater Boston, with a focus on discovering gaps and barriers. This is followed by a qualitative analysis that draws on survey results and case studies to offer deeper insights into program operations, including the challenges faced by different types of ESOL programs. This research points to six broad areas where strategic leadership and investment could lead to transformative changes in the ESOL system. They are: (1) the immense gap between the capacity of the system and the need for ESOL services; (2) the need for more and better ESOL teacher professional development; (3) the lack of student support services to ensure continuous participation; (4) the need to grow the number of vocational and workplace ESOL programs to help immigrant workers meet their long-term goals of improving their earnings and career prospects; (5) the fragmented nature of the system and need for coordination; and (6) the need to support data collection and reporting on ESOL programs and outcomes. [This report was produced by the Kitty and Michael Dukakis Center for Urban and Regional Policy and the Latino Legacy Fund.]