The iPhone Dev-Team has released RedSn0w 0.9.8b4 for developers to jailbreak iOS 5 Beta 4.
Just a few warnings to remember once again that this is a TETHERED jailbreak so be aware, the intention of this redsn0w release is for developers’ use only – use at your own risk and understand the consequences, risk and actions that may occur as a result of using this release. This continues to be a tethered jailbreak for all hardware, which includes the iPhone 3GS and the iPhone 4, iPod Touch 3G, iPod Touch 4G, and iPad 1. iPad 2 remains unsupported even now.It appears by design, the OTA update that became available starting with iOS 5 Beta 4 will not be automatically applied to jailbroken devices. That’s a relief to those who don’t want to lose their jailbreak vie OTA pushes. If you are jailbroken, you need to use the standard iTunes method to get iOS 5 Beta 4.
The jailbreak works like any other past version of redsn0w.THIS IS A TETHERED JAILBREAK ONLY! No new exploits are being exposed with this jailbreak (it uses geohot’s limera1n bootrom exploit), but that comes at a cost. You will need to use redsn0w to “Just boot tethered now” to be able to use many things, including Cydia and Safari. If you see a white icon for Cydia, or if Cydia or Safari crash when you open them, it’s because you didn’t boot tethered.
THIS JAILBREAK IS INTENDED ONLY FOR DEVELOPERS OF JAILBROKEN APPS! There are just too many broken components (Apple’s official apps, 3rd-party App Store apps, Cydia apps, MobileSubstrate apps, etc) for this to be useful to anyone but those who are truly looking to fix bugs in their iOS 5 jailbroken apps
The following links give you redsn0w 0.9.8b4 for mac and windows:
For Microsoft Windows users, you can download redsn0w 0.9.4b4 from here
For Mac users, you can download ressn0w 0.9.4b4 from here