So here comes the first iPhone OS 4.0 jailbreak tool; RedSn0w from the house of Dev-Team. iPhone Dev-Team has released RedSn0w 0.9.5 Beta to jailbreak iPhone OS 4.0 beta 1 for developers of jailbroken apps only. Redsn0w 0.9.5 beta uses the same pwnage2 DFU-mode exploit that dev-team has been using since the 2.x days.