Shareware in the context of Freely redistributable software

Doom is a 1993 first-person shooter game developed and published by id Software for MS-DOS. It is the first installment in the Doom franchise. The player assumes the role of a space marine, later unofficially referred to as Doomguy, fighting through hordes of undead humans and invading demons. The game begins on the moons of Mars and finishes in hell, with the player traversing each level to find its exit or defeat its final boss. It is an early example of 3D graphics in video games, and has enemies and objects as 2D images, a technique sometimes referred to as 2.5D graphics.

Doom was the third major independent release by id Software, after Commander Keen (1990–1991) and Wolfenstein 3D (1992). In May 1992, id started developing a darker game focused on fighting demons with technology, using a new 3D game engine from the lead programmer, John Carmack. The designer Tom Hall initially wrote a science fiction plot, but he and most of the story were removed from the project, with the final game featuring an action-heavy design by John Romero and Sandy Petersen. Id published Doom as a set of three episodes under the shareware model, marketing the full game by releasing the first episode free. A retail version with an additional episode was published in 1995 by GT Interactive as The Ultimate Doom.

An indie video game or indie game (short for independent video game) is a video game created by individuals or smaller development teams without the financial and technical support of a large game publisher, in contrast to most "AAA" (triple-A) games. Because of their independence and freedom to develop, indie games often focus on innovation, experimental gameplay, and taking risks not usually afforded in AAA games. Indie games tend to be sold through digital distribution channels rather than at retail due to a lack of publisher support. The term is analogous to independent music or independent film in those respective mediums.

Indie game development bore out from the same concepts of amateur and hobbyist programming that grew with the introduction of the personal computer and the simple BASIC computer language in the 1970s and 1980s. So-called bedroom coders, particularly in the United Kingdom and other parts of Europe, made their own games and used mail order to distribute their products, although they later shifted to other software distribution methods with the onset of the Internet in the 1990s, such as shareware and other file sharing distribution methods. However, by this time, interest in hobbyist programming had waned due to rising costs of development and competition from video game publishers and home consoles.

Freeware is software, often proprietary, that is distributed at no monetary cost to the end user. There is no agreed-upon set of rights, license, or EULA that defines freeware unambiguously; every publisher defines its own rules for the freeware it offers. For instance, modification, redistribution by third parties, and reverse engineering are permitted by some publishers but prohibited by others. Unlike with free and open-source software, which are also often distributed free of charge, the source code for freeware is typically not made available. Freeware may be intended to benefit its producer by, for example, encouraging sales of a more capable version, as in the freemium and shareware business models; or by collecting and selling user's personal data.

An indie video game or indie game (short for independent video game) is a video game created by individuals or smaller development teams, and typically without the financial and technical support of a large game publisher, in contrast to most "AAA" (triple-A) games. Because of their independence and freedom to develop, indie games often focus on innovation, experimental gameplay, and taking risks not usually afforded in AAA games. Indie games tend to be sold through digital distribution channels rather than at retail due to a lack of publisher support. The term is analogous to independent music or independent film in those respective mediums.

Indie game development bore out from the same concepts of amateur and hobbyist programming that grew with the introduction of the personal computer and the simple BASIC computer language in the 1970s and 1980s. So-called bedroom coders, particularly in the United Kingdom and other parts of Europe, made their own games and used mail order to distribute their products, although they later shifted to other software distribution methods with the onset of the Internet in the 1990s, such as shareware and other file sharing distribution methods. However, by this time, interest in hobbyist programming had waned due to rising costs of development and competition from video game publishers and home consoles.

Shovelware is a type of video game or software bundle known more for the quantity of what is included than for its quality or usefulness.

The metaphor implies that the creators showed little care for the quality of the original software, as if the new compilation or version had been created by indiscriminately adding titles "by the shovel" in the same way someone would shovel bulk material into a pile. The term "shovelware" is coined by semantic analogy to phrases like shareware and freeware, which describe methods of software distribution. It first appeared in the early 1990s when large amounts of shareware demo programs were copied onto CD-ROMs and advertised in magazines or sold at computer flea markets.

Commander Keen is a series of side-scrolling platform video games developed primarily by id Software. The series consists of six main episodes, a "lost" episode, and a final game; all but the final game were released for MS-DOS in 1990 and 1991, while the 2001 Commander Keen was released for the Game Boy Color. The series follows the eponymous Commander Keen, the secret identity of the eight-year-old genius Billy Blaze, as he defends the Earth and the galaxy from alien threats with his homemade spaceship, rayguns, and pogo stick.

The first three episodes were developed by Ideas from the Deep, the precursor to id, and published by Apogee Software as the shareware title Commander Keen in Invasion of the Vorticons; the "lost" episode 3.5 Commander Keen in Keen Dreams was developed by id and published as a retail title by Softdisk; episodes four and five were released by Apogee as the shareware Commander Keen in Goodbye, Galaxy; and the simultaneously developed episode six was published in retail by FormGen as Commander Keen in Aliens Ate My Babysitter. Ten years later, an homage and sequel to the series was developed by David A. Palmer Productions and published by Activision as Commander Keen. Another game was announced in 2019 as under development by ZeniMax Online Studios, but was not released.

Wolfenstein 3D is a 1992 first-person shooter game developed by id Software and published by Apogee Software and FormGen for DOS. It was inspired by the 1981 Muse Software video game Castle Wolfenstein, and is the third installment in the Wolfenstein series. In Wolfenstein 3D, the player assumes the role of Allied spy William "B.J." Blazkowicz during World War II as he escapes from the Nazi German prison Castle Wolfenstein and carries out a series of crucial missions against the Nazis. The player traverses each of the game's levels to find an elevator to the next level or kill a final boss, fighting Nazi soldiers, dogs, and other enemies with a knife and a variety of guns.

Wolfenstein 3D was the second major independent release by id Software, after the Commander Keen series of episodes. In mid-1991, programmer John Carmack experimented with making a fast 3D game engine by restricting the gameplay and viewpoint to a single plane, producing Hovertank 3D and Catacomb 3-D as prototypes. After a design session prompted the company to shift from the family-friendly Keen to a more violent theme, programmer John Romero suggested remaking the 1981 stealth shooter Castle Wolfenstein as a fast-paced action game. He and designer Tom Hall designed the game, built on Carmack's engine, to be fast and violent, unlike other computer games on the market at the time. Wolfenstein 3D features artwork by Adrian Carmack and sound effects and music by Bobby Prince. The game was released through Apogee in two sets of three episodes under the shareware model, in which the first episode is released for free to drive interest in paying for the rest. An additional episode, Spear of Destiny, was released as a stand-alone retail title through FormGen.