The original Forza Motorsport for Xbox was released on May 3, 2005, meaning Microsoft's racing series his now ten years old. Developer Turn 10 celebrated the news on Twitter, as did Xbox boss Phil Spencer. @ForzaMotorsport "May 3, 2005 it all began. Ten amazing years of Forza! Thanks to all our fans around the world." Phil Spencer ✔@XboxP3 "Congrats, it's been a good ride." Sequels in the core Forza series have been released every other year. 2005's Forza Motorsport was followed up by Forza Motorsport 2 in 2007, Forza Motorsport 3 in 2009, Forza Motorsport 4 in 2011, and Forza Motorsport 5 in 2013. The next game, Forza Motorsport 6, launches this fall for Xbox One.Microsoft created a Forza sub-brand called Forza Horizon in 2012, with its sequel Forza Horizon 2 released last fall. A standalone Forza spinoff inspired by Fast & Furious was released earlier this year.Forza Motorsport 6 details are being kept under wraps for now, but Microsoft is planning to reveal gameplay and talk more about the project at E3 next month. Source: GS