Question: Who is the protagonist in Ayn Rand's most notable novel?

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Nick Gaetano: Nick Gaetano is an artist, known for creating the 35th Anniversary Edition cover art for the works of Ayn Rand: "Atlas Shrugged", "The Fountainhead", "Anthem", "We the Living", "", "", "For the New Intellectual", "The Early Ayn Rand", "The Romantic Manifesto", and "The Virtue of Selfishness".  He also created The Ayn Rand Postage Stamp.  In 2002, the original art for the Anniversary Editions of "The Fountainhead" and "Atlas Shrugged" sold at auction for $118,000.

The Fountainhead: The Fountainhead is a 1943 novel by Russian-American author Ayn Rand, her first major literary success.  The novel's protagonist, Howard Roark, is an individualistic young architect who designs modernist buildings and refuses to compromise with an architectural establishment unwilling to accept innovation.  Roark embodies what Rand believed to be the ideal man, and his struggle reflects Rand's belief that individualism is superior to collectivism.

The Atlas Society: The Atlas Society (TAS), formerly known as the Institute for Objectivist Studies and then as The Objectivist Center, is an American Objectivist research and advocacy organization that "promotes open Objectivism: the philosophy of reason, individualism, achievement, and freedom originated by Ayn Rand".  It is part of the Objectivist movement that split off from the Ayn Rand Institute in 1990 due to disagreements over whether Ayn Rand's philosophy of Objectivism was a "closed system" or an "open system".  Jennifer Grossman is the CEO of the organization.

Harry Binswanger: Harry Binswanger ( ; born 1944) is an American philosopher.  He is an Objectivist and on the board of the Ayn Rand Institute.  He was an associate of Ayn Rand, working with her on "The Ayn Rand Lexicon".  He helped edit the second edition of Rand's "Introduction to Objectivist Epistemology".  His most recent book is "How We Know: Epistemology on an Objectivist Foundation" (2014).

Judgment Day: My Years with Ayn Rand: Judgment Day: My Years with Ayn Rand is a 1989 memoir by Nathaniel Branden that focuses on his relationship with his former mentor and lover, Ayn Rand.  Branden released a revised version, retitled as My Years with Ayn Rand, in 1999.

Objectivism: The Philosophy of Ayn Rand: Objectivism: The Philosophy of Ayn Rand is a 1991 book by philosopher Leonard Peikoff, in which the author discusses the ideas of his mentor, Ayn Rand.  Peikoff describes it as "the first comprehensive statement" of Rand's philosophy, Objectivism.  The book is based on a series of lecture courses that Peikoff first gave in 1976 and that Rand publicly endorsed.  Peikoff states that only Rand was qualified to write the definitive statement of her philosophic system, and that the book should be seen as an interpretation "by her best student and chosen heir."  The book is volume six of the "Ayn Rand Library" series edited by Peikoff.

Objectivism (Ayn Rand): Objectivism is a philosophical system developed by Russian-American writer Ayn Rand (1905–1982).  Rand first expressed Objectivism in her fiction, most notably "The Fountainhead" (1943) and "Atlas Shrugged" (1957), and later in non-fiction essays and books.  Leonard Peikoff, a professional philosopher and Rand's designated intellectual heir, later gave it a more formal structure.  Peikoff characterizes Objectivism as a "closed system" that is not subject to change.

Objectivist movement: The Objectivist movement seeks to study and advance Objectivism, the philosophy of Ayn Rand.  It was founded by novelist, screenwriter, and philosopher Ayn Rand.  The movement began informally in the 1950s and consisted of students who were brought together by their mutual interest in Rand's novel, "The Fountainhead".  The group, ironically named "the Collective" due to their actual advocacy of individualism, in part consisted of Nathaniel Branden, Barbara Branden, Alan Greenspan, and Leonard Peikoff.  Nathaniel Branden, a young Canadian student who had been greatly inspired by Rand's work, became a close confidant and encouraged Rand to expand her philosophy into a formal movement.  From this informal beginning in Rand's living room, the movement expanded into a collection of think tanks, academic organizations, magazines, and journals.

Ayn Rand Institute: The Ayn Rand Institute: The Center for the Advancement of Objectivism, commonly known as the Ayn Rand Institute (ARI), is a nonprofit think tank in Irvine, California, that promotes Objectivism, a philosophical system developed by author Ayn Rand.  Its stated goal is to "spearhead a cultural renaissance that will reverse the anti-reason, anti-individualism, anti-freedom, anti-capitalist trends in today's culture".  The organization was established in 1985, three years after Rand's death, by Leonard Peikoff, Rand's legal heir.  Jim Brown is the current CEO of ARI, succeeding Yaron Brook in January 2017.

The Journal of Ayn Rand Studies: The Journal of Ayn Rand Studies (JARS) is an academic journal devoted to the study of the philosophy of Ayn Rand.  Established in 1999, its founding co-editors were R. W. Bradford, Stephen D. Cox, and New York University scholar Chris Matthew Sciabarra.  At present, the editorial board consists of Robert L. Campbell, Stephen D. Cox, Roderick Long, and Chris Matthew Sciabarra.  Since 2013, the journal has been published by Pennsylvania State University Press.  Although the Objectivist movement of supporters of Rand's philosophy has been criticized as being a cult of personality, "The Journal of Ayn Rand Studies" often publishes papers by mainstream intellectuals and academics from prestigious universities worldwide that approach Rand's legacy without hagiography.

Supporting paragraphs: Objectivism (Ayn Rand) The Fountainhead
Answer: Howard Roark