Factor 5 GmbH is an independent software and video game developer. The company was originally co-founded by five former Rainbow Arts employees in 1987 in Cologne, Germany, which served as the inspiration behind the studio's name, before relocating to San Rafael, California in 1994. While its founders were still university students, Factor 5 started out in game development as a part-time activity under partnership with Rainbow Arts for the Amiga computer. There, they had their earliest moderate success with Katakis, an R-Type clone of impressive technical performance. Due to the game's obvious similarity to R-Type, rights holder Activision Europe delivered an ultimatum: either Factor 5 accept a contract to perform the official R-Type conversion for the Amiga home computer, or receive a lawsuit for rights infringement. According to Julian Eggebrecht, this was because "Activision couldn't find any programmers" however the opportunity was "a dream come true".
- May 1996, Factor 5, Inc. was established in the United States with legal support from LucasArts.
- May 2009, Factor 5, Inc. was shut down following the closure of Brash Entertainment, with which the company had multiple contracts.
- January 2011, Moller liquidated Factor 5 GmbH, and all game licenses were transferred to Eggebrecht, Engel, Schmidt GbR.
- March 15 2017, Co-founder Julian Eggebrecht had announced that the company has returned and reacquired the rights to the Turrican franchise.