Redsn0w for Mac
Redsn0w is the most popular jailbreaking tool amonug the Mac users. Redsn0w is more compatible with Mac OS. You can jailbreak your apple devices with Redsn0w for 100% free
You have to use correct Redsn0w version according to your apple device and iOS firmware. If your device is the new one just like iPhone 3GS, iPhone4, iPad, iPod 4G with latest iOS firmware ( 5.0.0 , 5.0.1, 5.1.0) we recommend to use latest Redsn0w version.
If your device is iPhone4S or iPad 2 you still can't jailbreak it with redsn0w. You have to use good redsn0w alternative for jailbreak these devices