Dozens gathered for a self publishing party at Politics and Prose on Jan. 26, 2013. (John Wilwol/For The Washington Post)

Since it arrived a year ago at Politics & Prose, “Opus,” Washington’s first print-on-demand Espresso book machine, has helped hundreds of area scribblers realize their publishing dreams. On a gray, biting afternoon Saturday, a dozen of them gathered at the bookstore to delight a standing-room-only audience with selections from their work. It was the first-ever Opus open mike.

Picked by a lottery open to all Opus authors, the diverse group brought poems, novels, memoirs and biographies. Before the writers came to the lectern, marketing director Lacey Dunham — timecards in hand — warned them not to break the five-minute limit: “I used to be a teacher!”

Joseph T. Wilkins, dressed in a red tie, white shirt and blue blazer, kicked things off with a lively introduction to “The Speaker Who Locked Up the House,” his historical novel about late-19th-century House Speaker Thomas Brackett Reed. “It’s a fat sucker,” he said of the book. “If you like history, you’ll like this.” A former municipal judge, Wilkins lives outside Atlantic City and comes to the District regularly for research. When he heard about Opus, he said, he was “fascinated by it.”

The Espresso book machine looks like a giant copier. Feed in a digital manuscript, and in a few minutes the machine produces a bound paperback, complete with a color cover. One of only a few operating in independent bookstores worldwide, the machine at Politics & Prose has produced about 9,000 books so far.

The service can be a particularly useful tool for teachers. John Nelson and Tymofey Wowk, who teach English for non-native speakers at the University of Maryland Baltimore County, used Opus to create their dream textbook, “Making English Grammar Meaningful and Useful.” On Saturday, they quizzed the audience with exercises from the book.

“How many forms do most English verbs have?” Nelson asked. “Two!” a man eagerly answered. “Try five,” Nelson said. “Now, how many verb tenses does American English have?” “Five!” the same man called out. The correct answer, Wowk said, is 12. “As you can see,” Nelson said, “it can be really difficult to learn this stuff because there’s zero logic to it.”

Poetry journals may be hard to break into, but Sonja Plummer, an Ashburn writer, has used Opus to print three collections of her verse. Standing confidently at the mike, she read several of her works, including the title poem from her collection “Piece by Piece: Love Poems”: “Kiss me / I may break / Then hold me / Piece by Piece / In your arms so / I may live again.”

The afternoon’s most poignant moment was when D.C. freelance editor and calligrapher Clare Dickens read from her memoir, “A Dangerous Gift,” which chronicles her son Titus’s struggle with bipolar disorder. He took his own life at age 25. Dickens, who has an English accent, began with the introduction, which was written by Titus: “This is the story of how I lost my light,” she read. “In fact I hope to rekindle it by writing this.” In a later section of the book, she recalled the questions that still haunt her: “How was it possible for me to be scared to confront my own son; the little curly haired 10-year-old who one night I discovered was sleeping with a Bible under his pillow — ‘to help make him good.’ ”

The day’s spirit was best captured by D.C. writer John Kelley, who read from his self-published novel, “The Fallen Snow,” about a World War I vet’s difficult return to Virginia. “Not many debut novelists,” he pointed out, “get to say their first reading was at Politics & Prose.”

Wilwol is a freelance writer in Washington.