The iPhone Dev-Team has released an update to their UltraSn0w unlock bringing support for iOS 5. Remember that NO new basebands are supported in this release. It only adds support for iOS 5 with old basebands.
Here is the list of supported basebands:
If have one of the above baseband version and need unlock you can upgrade to iOS 5 without updating your baseband using .
Ultrasn0w 1.2.4 is available in Cydia.
The iPhone Dev-Team has released RedSn0w 0.9.9b5 – an official tethered jailbreak for iOS 5. Users don’t have to point to downloaded iOS 5 ipws any more. Just run and jailbreak.
Currently only the Mac version has been made available. Windows version is coming soon. However Windows users can still jailbreak iOS 5 with Redsn0w 0.9.9.b4, – just go to “Extras” -> “Select IPWS” and select your iOS 5 ipsw file (can download ).
Good news for users who need carrier unlock (ultrasn0w or Gevey Sim). With RedSn0w 0.9.9b5 you can update to iOS 5 and preserve the baseband (modem) version for unlock:
The new “Custom IPSW” button on the Extras screen will create a custom IPSW without the baseband update for 4.3.3 or 5.0gm (iPhone3GS and iPhone4 only, for now). Remember not to accidentally restore to the stock IPSW after you create the custom one! The custom one begins with NO_BB_ (for “no baseband”).
You must enter “Pwned DFU” mode before trying to use the NO_BB_ IPSW with iTunes (and your hosts file cannot be pointing to Cydia’s servers due to the new blob nonce mechanism they’re using in iOS5).
We will update our step-by-step tutorials soon.
You can download RedSn0w 0.9.9b5 (Mac) and RedSn0w 0.9.9b4 (Windows) .
PS: RedSn0w 0.9.9 is a bit different from 0.9.8 version. You can learn more about other new redsn0w 0.9.9 features .
UPDATE: redsn0w 0.9.9b6 released, download
UPDATE:
Here are links to our RedSn0w 0.9.9 iOS 5 jailbreak tutorials:

UPDATE: Apple latest firmware is iOS 5.1.1. Apple has stopped signing all other firmwares, including iOS 5.0.1, iOS 4.3.3 and iOS 4.3.5. This means you can NOT restore to 5.0.1/4.3.3/4.3.5 any more (both original and custom), unless you have saved your SHSH keys for it.
If you have decided to perform an untethered jailbreak and unlock, you need to get the following information:
For iPhone 3G the latest is iOS 4.2.1. You can perform jailbreak with any utility. For iOS 4.2.1 you can also use them or GreenPois0n (Windows, Mac OS).
iPad 2 jailbreak is available only for iOS 4.3.3 via JailbreakMe and and iOS 5.0.1 via Absenthe.
iPhone 4S jailbreak is available for iOS 5.0 / iOS 5.0.1 via Absenthe.
Apple stopped signing iOS 4.3.3, so you cannot update to iOS 4.3.3 without SHSH keys saved (in advance some time ago). If you have , iPhone 3GS, iPad 1, iPod Touch 3G or iPod Touch 4G that run iOS 4.3.3 – use JailbreakMe or RedSn0w to untether jailbreak your device.
If you have saved SHSH keys for iOS 4.3.3 you can use PwnageTool (Mac OS) or Sn0wBreeze (Windows).
For iOS 4.3.4/4.3.5 only tethered jailbreak is possible with redsn0w. Tethered means that each time you restart your device you will have to connect it to a computer and run redsn0w. The untethered iOS 4.3.5 jailbreak is possible only for iPhone 3GS with old bootrom. You can detect your bootrom version using .
To jailbreak and unlock iOS 5 use latest version of redsn0w 0.9.9 or sn0wbreeze 2.8. You can jailbreak tethered or .
The untethered iOS 5 jailbreak is possible only for iPhone 3GS with old bootrom. You can detect your bootrom version using .
For iPhone 4/3GS, iPad 1, iPod Touch 3G/4G an untethered jailbreak is available for iOS 5.0.1. For untethered jailbreak use the latest redsn0w 0.9.10 or Corona – package from Cydia to untether currently installed tethered jailbreak.
Tutorial how to untether installed tethered jailbreak is available .
For iPhone 4S and iPad 2 use Absenthe.
For tethered iOS 5.0.1 jailbreak you an use redsn0w 0.9.9 and sn0wbreeze 2.8.
For now only tethered jailbreak is available for iPhone 4/3GS, iPad 1 and iPod Touch 3G/4G for iOS 5.1 and iOS 5.1.1.
You can download all firmwares .
Here are our step-by-step tutorials that will guide you through the jailbreak process:
iPhone 4S
UnTethered jailbreak iOS 5.0 / iOS 5.0.1:
iPhone 4
Tethered jailbreak iOS 5.1.1:
Tethered jailbreak iOS 5.1:
UnTethered jailbreak iOS 5.0.1:
Semi-Tethered jailbreak iOS 5:
Tethered jailbreak iOS 4.3.5:
UnTethered jailbreak iOS 4.3.3:
The iPhone Dev-Team has released RedSn0w 0.9.8b7b to bring two new main features:
Musclenerd posted via twitter:
New redsn0w is.gd/6eek4Y explicitly supports iOS5b7 (no need to point at b6 IPSW). Also brings back old-bootrom 3GS goodies.
This is great news for both developers and owners of old bootrom iPhone 3GS’s who accidentally updated to iOS 4.3.5.
DevTeam posted:
About 12 hours after we released redsn0w 0.9.8b7 with some improvements for iOS5b6, Apple went and released iOS5b7 (what are the odds of that?!?). Even though that redsn0w could still jailbreak iOS5b7, you needed to point it at the iOS5b6 IPSW to do so. Today’s redsn0w 0.9.8b7b lets you point redsn0w directly at the iOS5b7 IPSW instead.
We’ve also added some overall improvements for old-bootrom 3GS owners (where the 24kpwn exploit applies): on those devices, you can tell redsn0w to untether 4.3.5 and lower, or iOS5b7. Old-bootrom 3GS owners can once again choose custom logos, and/or verbose booting (for the really nerdy iPhone3GS fans out there!). And it allows 4.3.4 or 4.3.5 users to use ultrasn0w again (if they have a compatible baseband).
Last but not least, we fixed some lingering Verizon 4.2.10 JB issues.
We will update our tutorials shortly.
You can download RedSn0w 0.9.8b7b .
Here are links to our RedSn0w 0.9.8b7b iOS 4.3.5 jailbreak tutorials:

MuscleNerd, the iPhone Dev-Team member, has announced via Twitter that developers can use RedSn0w 0.9.8b7 to jailbreak iOS 5 Beta 7.

MuscleNerd: Today’s iOS5b7 can be JB with last night’s redsn0w b7 http://is.gd/6eek4Y but point it at b6 IPSW…annoying off-by-1 now 🙂
You can download RedSn0w 0.9.8b7 . iOS 5 Beta 7 is available for developers and for everybody else.
The iPhone Dev-Team recently released RedSn0w 0.9.8b7 which brings explicit support for a tethered 4.3.5 jailbreak as well as new iOS 5.0b6 iPad 1 jailbreak:
Apple updated the iPad1 iOS5b6 IPSW without changing its version number or filename, so we’re releasing redsn0w 0.9.8b7 to handle both the original and changed IPSW. We’ve also added explicit support for a tethered 4.3.5/4.2.10 jailbreak (instead of pointing at the 4.3.4/4.2.9 IPSWs) and fixed a 4.2.10 problem.
You can download RedSn0w 0.9.8b7 .
You can find our instructions on how to jailbreak your device here:
iPhone 3GS
Tethered and UnTethered jailbreak iOS 4.3.5:
Tethered jailbreak iOS 4.3.5:
iPad 1
Tethered jailbreak iOS 4.3.5:
iPod Touch 3G
Tethered jailbreak iOS 4.3.5:
iPod Touch 4G
Tethered jailbreak iOS 4.3.5:
The iPhone Dev-Team released RedSn0w 0.9.8b6 that supports tethered jailbreak for the most recent iOS 5 beta 6:
We’ve released redsn0w 0.9.8b6 to jailbreak iOS5 beta6 (point it directly at the beta6 IPSW).
Two important notes about this version:
(1) Please let your device boot normally to IOS5b6 and do a clean shutdown (slide to power off) before jailbreaking.(2) Boot logos have intentionally been disabled for now, so you’ll see a black screen on tethered boots (you can re-enable logos or verbose boot with command-line options if you really want them back).
Due increased sensitivity to abrupt filesystem shutdowns in IOS5b6, it’s very important that you do a clean shutdown before running redsn0w.
RedSn0w 0.9.8b6 supports tethered jailbreak for , iPhone 3GS, iPod Touch 3G, iPod Touch 4G and iPad 1.
You can download RedSn0w 0.9.8b6 for Windows and Mac OS .
The iPhone Dev-Team released RedSn0w 0.9.8b5 that supports tethered jailbreak for the most recent iOS 5 beta 5:
redsn0w has been updated to 0.9.8b5, adding support for Apple’s new iOS5 beta5 (point it directly at the beta5 IPSW). Please use this only if you’re a jailbreak app developer with a legit Apple dev account, and remember it’s a tethered jailbreak for now!
You can download RedSn0w 0.9.8b5 for Windows and Mac OS .

RedSn0w can perform a tethered jailbreak on iOS 4.3.5 for all devices except the iPad 2, according to MuscleNerd’s tweet:
So those who really do want tethered 4.3.5 can use redsn0w pointed at 4.3.4 (except iPad2)
We strongly recommend NOT to update to iOS 4.3.4 or iOS 4.3.5 to preserve untethered jailbreak. We will soon post step-by-step tutorials on how to perform iOS 4.3.5 tethered jailbreak.
You can download the latest redsn0w .
UPDATE: Here are latest step-by-step tutorials to jailbreak iOS 4.3.5:
iPhone 3GS
Tethered jailbreak iOS 4.3.5:
Tethered jailbreak iOS 4.3.5: