The Mural Arts Program of Philadelphia began in 1984 as a summer youth program with modest support from city government. Under the guidance of Jane Golden, however, it gradually grew into one of the largest and most successful public art organizations in the country, garnering support from local corporations, foundations, and individuals to extend the reach and effectiveness of its innovative programs.    Now three decades later, the Mural Arts Program has created more than 3,800 murals and public art projects that have made lasting imprints in every Philadelphia neighborhood. In the process, Mural Arts has engaged thousands of people of all ages from across the city, helped hundreds of ex-offenders train for new jobs, transformed the face of struggling commercial corridors, and developed funding partners in both public and private sectors.     While the Mural Arts Program has significantly changed the appearance of the city, it has also demonstrated how participatory public art can empower individuals and promote communal healing around difficult issues. Philadelphia Mural Arts @ 30 is a celebration of and guide to the program's success. Unlike Philadelphia Murals and the Stories They Tell and its sequel, More Philadelphia Murals and the Stories They Tell, Philadelphia Murals @ 30 showcases the results of 21 projects completed since 2009 and features essays by policy makers, curators, scholars, and educators that offer valuable lessons for artists, activists, and communities to emulate.   Philadelphia Mural Arts @ 30 traces the program's history and evolution, acknowledging the challenges and rewards of growth and change while maintaining a core commitment to social, personal, and community transformation.     Contributors include: Dr. Arthur C. Evans, Jr., Arlene Goldbard, Thora Jacobson, Rick Lowe, Dr. Samantha L. Matlin, Paulette Moore, Jeremy Nowak, Maureen H. O'Connell, Elisabeth Perez Luna, Robin Rice, Dr. Jacob Kraemer Tebes, Elizabeth Thomas, Cynthia Weiss, Howard Zehr, and the editors.