Developers iH8Sn0w, SquiffyPwn and winocm have released an untethered jailbreak for iOS 6.1.3 and iOS 6.1.5 for Windows and Mac OS X users.
p0sixspwn jailbreak supports iPhone, iPad or iPod Touch running on iOS 6.1.3 through iOS 6.1.5.
For p0sixspwn jailbreak you require iPhone 3GS, iPhone 4 or iPod Touch 4G running on older firmwares.
P0sixspwn 1.0.3 can be downloaded for Windows whereas p0sixspwn 1.0.2 is the latest version available for Mac OS X.
P0sixspwn 1.0.2 for Mac jailbreak tool fixes issues with LTE and issues with users running Mac OS X Lion 10.7.
Download Posixspwn Jailbreak for Windows and Mac OS X
Take a back up of your device using iTunes before jailbreaking your device!