For almost as long as there have been computers, there have been people intent in playing games with them. Since young programmers at the Massachusetts Institute of Technology came up with "Spacewar!" some 50 years ago, the world of videogames has exploded into a multi-billion-dollar industry. "From the earliest days of computer, these folks went after computer graphics and went after videogames," Gartner consumer technologies research director Brian Blau told AFP. "People enjoy games, and marrying the concept of real-world games with a computer and interactivity is really powerful." Gartner predicts the worldwide videogame market combining console, online, mobile, and personal computer offerings will expand from $101 billion this year to $111 billion next year and top $128 billion in 2017. While play on high-performance desktop or laptop computers has long captivated hardcore videogame lovers, rival console makers Microsoft, Sony, and Nintendo have successfully turned games into standard family household entertainment during the past 20 years, with Xbox, PlayStation and Wii hardware respectively. - Console Kings - New-generation Xbox One and PlayStation 4 consoles released late last year are credited with bringing new life to a section of the market under pressure from the popularity of of smartphones and tablets. But Nintendo's latest console, Wii U, has had trouble gaining traction among players. Console kings are also the big names behind titles for play on their hardware, but third-party studios such as Activision Blizzard, Electronic Arts, Ubisoft, Disney Interactive, and Warner Brothers are established titans in game software. While movie-like immersion in play and broadening entertainment menus to include streamed films and television shows has consoles proving their worth, mobile games are on fire. There are more game "apps" for smartphones or tablets than any other type of mini-program for mobile devices and it is the top revenue-producing category, according to Gartner. - Apps on fire - Smartphones and tablets have lured players from dedicated handheld mobile game devices that, for a time, were a hit with people who wanted to play on the go. Mobile game revenues can come from people paying to download "apps" or from in-game transactions in which players poney-up to advance more quickly through levels or buy abilities or digital items. Britain-based King Digital Entertainment, which is behind a Candy Crush Saga game craze, is set for a keenly-anticipated stock market debut. Other sizzling mobile game firms include Rovio, Wooga, and Supercell. Even Zynga, which pioneered online social games only to get caught on its heels when players turned to mobile devices, is not out for the count. The San Francisco company is intent on reviving a lineup that includes "Farmville" and "Words With Friends" along with a popular Zynga Poker title. Mobile game revenue globally is set to nearly double in the next two years to $22 billion, according to Gartner. - Spectator sport - A new and flourishing eSport category in which videogame play is spectator sport complete with commentators, sponsors and ads has yet to be factored into the global videogame revenue model. "Computer graphics represent a new interaction paradigm," Blau said. "Today's high-detail graphics and more immersive experiences are almost science fiction-like." Innovations in game hardware and software from Internet-linked eyewear to augmented reality programs are expected to fuel increasing demand for play.