The F Market & Wharves line is one of several light rail lines in San Francisco, California. Unlike most other lines in the system, the F line runs as a heritage streetcar service, using exclusively historic equipment both from San Francisco's retired fleet as well as from cities around the world. While the F line is operated by the San Francisco Municipal Railway (Muni), its operation is supported by Market Street Railway, a nonprofit organization of streetcar enthusiasts which raises funds and helps to restore vintage streetcars.