Who is the main character in Speed-the-Plow by David Mamet?

As a playwright, Mamet is often praised by critics for his realistic dialogue. Mamet writes dialogue in a way that reflects how people really talk to each other. Words overlap, people interrupt each other, and sentences are often short and complete with pauses. In Speed-the-Plow, Mamet's language choices reflect his subject matter. Charlie Fox and Bobby Gould use Hollywood cliches (the buddy picture, for example) and other lingo (greenlighting a picture), to set the tone. Sometimes characters hide behind these cliches. For example, when Karen serves coffee to Fox and Gould, they use more Hollywoodspeak to emphasize their positions of power within the business to the self-described naive woman.