Question: Who is the owner of a small publishing firm focused on a series of related science fiction role-playing games, the first published in 1977 by Game Designers' Workshop?
Context: MegaTraveller 1: The Zhodani Conspiracy is a 1990 space science fiction role-playing video game based on the "Traveller" series and was produced by Game Designers' Workshop licensee Paragon Software for Amiga, Atari ST and MS-DOS operating environments.  The game is set within the "Official Traveller Universe" and features character creation and other aspects of game mechanics compatible with prior "Traveller" products.  The player controls up to five ex-military adventurers whose objective is to save their civilization, the Imperium, from a conspiracy instigated by the Zhodani, a rival spacefaring race, and aided by the actions of a traitor named Konrad Kiefer.  Gameplay features real-time planetary and space exploration, combat, trading, and interaction with various non-player characters in eight solar systems containing twenty-eight visitable planets. Earl Kemp (born November 24, 1929) is an American publisher, science fiction editor, critic, and fan who won a Hugo Award for Best Fanzine in 1961 for "Who Killed Science Fiction", a collection of questions and answers with top writers in the field.  Kemp also helped found Advent:Publishers, a small publishing house focused on science fiction criticism, history, and bibliography, and served as chairman of the 20th World Science Fiction Convention.  During the 1960s and '70s, Kemp was also involved in publishing a number of erotic paperbacks, including an illustrated edition of the "Presidential Report of the Commission on Obscenity and Pornography."  This publication led to Kemp being sentenced to one year in prison for "conspiracy to mail obscene material," but he served only the federal minimum of three months and one day. MegaTraveller 2: Quest for the Ancients is a 1991 space science fiction role-playing video game produced by Game Designers Workshop licensee Paragon Software and distributed by MicroProse and Empire Software.  It is the sequel to "".  Designed by Marc Miller, an original creator of the "Traveller" series, the game is set within the "Official Traveller Universe" and features a character creation system and other elements of game mechanics compatible with previous "Traveller" products.  The game's plot centers on finding a way to stop the flow of slime issuing from an ancient ruin on the planet Rhylanor before it inundates the entire world.  Gameplay involves controlling a party of up to five adventurers who engage in real-time exploration, trading, interaction with non-player characters, combat and problem solving on the surface of over a hundred planets and in spaceships journeying between these worlds. Shining (シャイニング , "Shainingu" ) is a series of fantasy video games developed by Sega.  The series is Sega's main venture into the role-playing genre, along with the science fiction role-playing series "Phantasy Star".  The first game, "Shining in the Darkness", was a first-person dungeon crawler with randomly encountered, turn-based battles (comparable to "Wizardry" and "Might and Magic").  The next game released in the series was "Shining Force", which were turn-based strategy style tactical role-playing games with battle scenes acted out with sprites (comparable to the Kure Software Koubou games and "Fire Emblem").  Other spin-offs include "Shining Soul", a dungeon crawl action role-playing game with roguelike elements. Traveller is a series of related science fiction role-playing games, the first published in 1977 by Game Designers' Workshop.  Marc W. Miller designed "Traveller" with help from Frank Chadwick, John Harshman, and Loren K. Wiseman. "Traveller" is an Origins Award winning science fiction role-playing game published by Game Designers' Workshop in 1977.  In the Third Age of the Imperium interstellar travel has become possible and Humaniti has met other starfaring races.  2300 AD portrayed humans as technologically advanced, but having a level of civilization not very far above the present day.  Later publishers introduced additional material along the Official Traveller Universe (OTU) timeline.  In 2008, Mongoose Publishing reintroduced GDW's popular look and indexing feature separating publications into familiar Books, Supplements, and Adventures. Roger Sanger is an American game designer and the owner of Digest Group Publications, a small publishing firm focused on the role-playing game market and specifically on the game "Traveller". The miniatures game Striker was a science fiction tactical wargame that was published by Game Designers' Workshop in 1981 as a boxed expansion to the "Traveller" role-playing game.  It was notable for attempting to cover a broad range of technological levels and having an intricate "engineering" style of vehicle design by the player using formulas and tables.  The combat rules were an elaboration on the rules introduced in the Azhanti High Lightning game, using a 2D6 mechanic very different from the original "Traveller" rules.  A later game, "Striker II", was based on the systems in GDW's Command Decision World War II rules and tied to the role-playing game "". Traveller is a concept album by the American folk/power metal band The Lord Weird Slough Feg.  The album is based on Game Designers' Workshop's 1977 science fiction role-playing game, "Traveller". 2300 AD is a hard science fiction tabletop role-playing game created by Game Designers Workshop, originally offered as an alternative to the space opera portrayed by the company's leading science fiction role-playing game, "Traveller".  In fact it was originally titled "Traveller: 2300", but this caused confusion as the game used neither the rules system nor the setting of the original "Traveller".  The game was therefore renamed in its 2nd edition.
Answer: Roger Sanger