Original: Call of Duty 4 : Modern Warfare ( or Call of Duty : Modern Warfare ) is a first-person shooter video game , developed by Infinity Ward and published by Activision for PC , Macintosh , PlayStation 3 , Xbox 360 and Wii .
Simplified: Call of Duty 4 : Modern Warfare is a first person shooter videogame released in 2007 . It is part of the Call of Duty series .