It was just last week that the same RC5 jailbreak was launched for the AT&T iPhone 4 for Mac and Windows devices. The Chronic Dev Team must have been hard at it to get GreenPois0n 4.2.1 for the Big Red version of Apple’s smartphone out, and we cannot help but be happy for those who wish to free their phone with the use of Cydia.

Engadget has learned that there is a tutorial guide over on Quickpwn, bit as always warns that you jailbreak your device at your own risk. We know that it might not be illegal in the States, but there have been cases where it can brick your iPhone – so just be careful.

Darren Murph wonders if it will affect the performance on your Verizon iPhone 4 in anyway, as this is the first time that it has been jailbreaked on the carrier? For more details on this and links to download GreenPois0n 4.2.1 for the Verizon iPhone visit Blogsdna.

As reported from RedmondPie, the Chronic-Dev Team have just released a video which teases the new untethered jailbreak in action. Just so you’re fully aware, this jailbreak on iOS 4.2.1 will not require the 4.2b3 SHSH Blobs that were needed when using the Redsn0w 0.9.7 jailbreak.

Sadly, we don’t have an exact date for when this new untethered GreenPois0n update will release, but you can at least put your mind at ease in that it’s definitely on the way soon. You can check out the video in question below to see it working for yourself.

We’ll be informing you as soon as this download becomes available, but for instant updates on the untethered jailbreak, you can visit the official GreenPois0n website here, and also p0sixninja’s Twitter account here.

Are you waiting for this new and improved iOS 4.2.1 untethered jailbreak?

As reported from RedmondPie, the Chronic Dev-Team confirmed the news in a recent status update on Twitter, adding that the open source tools for GreenPois0n will be available once the main release moves out of beta.

What will an open source release of GreenPois0n mean though? Well, it will essentially allow developers and other members of the public access to all the tools within GreenPois0n, allowing them to modify it with extra features and tweaks to their liking.

We don’t have a release ETA for the open source version of GreenPois0n yet, but we’ll let you know as soon as it becomes available. If you have any current problems on GreenPois0n, visit our issues thread here.

As reported from RedmondPie, it now means that the new Apple TV hardware will be able to run things like iPhone applications and other cool tweaks, as soon as developers get working on it.

The creators of GreenPois0n have yet to disclose any download links or tutorials, but you can bet that a release ETA is not too far off after this screenshot proof of a jailbroken Apple TV running iOS 4.1.

The hardware has only been on sale a few weeks, so Apple will be no doubt furious over this. Check out the screenshot below and let us know your thoughts on this, particularly if you have already bought a 2G Apple TV box.

Sadly there is still no Mac version available, it seems as if the Dev Team are experiencing problems with this release, however are still very keen to release it.

23 hours ago there was a tweet on the ChronicDevTeam’s Twitter feed which read “Mac release is being worked on. Some technical difficulties must be resolved”, soon after they also tweeted “We have no ETA for the Mac release besides “soon”. Bad things seem to happen when we give ETAs”.

If you are a Linux user we would love to hear if the Linux version of Greenpois0n worked for you, if not let us know what problems you are experiencing, please remember to state which Linux distro you are using and which Apple device and version you are trying to jailbreak.

Gamal Sabry from Covering Web has a nine-step guide on how to get Greenpois0n installed on your Apple smartphone, just for those who have had a bit of trouble.

The first step is the easy part, downloading the jailbreak, with the second step making certain that you have your handset connected to your computer before launching the Greenpois0n app.

The following steps are shown by a series of images on the Covering Web website, which certainly makes it much simpler to understand. Once you have followed all of the steps that Sabry describes, please let us know if the guide was of any help to you.

The good news is that we have received some comments suggesting that it is working pretty well, however as you would expect some people are still experiencing error messages etc.

I think it would be fair to say that Greenpois0n is not perfect as some people had to run it a few times before it worked, one reader suggests that not switching off their iPod Touch 3rd-gen (running iOS 4.1) at the start resulted in Greenpois0n working, so perhaps try that.

The most common problem seems to result in Greenpois0n saying that it cannot detect DFU mode, I have looked around for a fix to no avail, therefore if anyone knows of a workaround please let us know in the comments section below.

The Chronic Dev Team recently tweeted “if u need some help we are offering some support go to IRC: irc.chronic-dev.org #greenpois0n”, I do not use IRC, however this could prove to be a very useful way of getting round all of your Greenpois0n problems. Another tweet explained that you must upgrade to iOS 4.1 on your iPhone/iPod Touch beforehand and 3.2.2 on your iPad.

Feel free to describe any problems you have in the comments section below, we will do our utmost to point you in the direction of fixes and workarounds when we find them.

Update: If you are still having problems check out the video embedded below, it has apparently helped some of our readers with the Limera1n and Greenpois0n jailbreak.

They revealed this in a tweet earlier today, sadly only the Windows version is up at the moment, however there is a Mac version being developed which will be coming soon.

You can download the Greenpois0n jailbreak here, the download itself is just 347kb in size and contains one exe, you can see a screenshot from the app at the end of this post.

The Greenpois0n jailbreak works with iPhone 4, iPhone 3G S, iPod touch (4th and 3rd Gen) and iPad, if you are using Greenpois0n on your iPhone 4 running iOS 4.1 you must use TinyUmbrella (here) to preserve your baseband.

Some early users suggest that Greenpois0n does not work, therefore we would appreciate your feedback in the comments section below.

Did Greenpois0n work for you? (Please state what device you was using and what Windows version you are running).

Source: ChronicDevBlog

It was no secret that the Chronic Dev Team were upset that Geohot released Limera1n before GreenPois0n. However, iOS users were happy, as this latest jailbreak worked on most iOS devices. You can imagine that users were upset with this delay – but they still seem to be waiting patiently.

There are fears that GreenPois0n could be delayed by at least a month, if this is the case then it will no longer be an iOS 4.1 jailbreak; this is because that will be about the time when Apple releases iOS 4.2 for public download.

If you had to wait another month, would you begin to loose faith in the Chronic Dev Team?

According to this report from RedmondPie, Geohot has created a new bootrom exploit for LimeRa1n, meaning that the new version will support the iPhone 3G, 3GS and iPod Touch 3G, along with the new iPhone 4 and iPod Touch 4G.

If you didn’t know, Geohot seemingly quit the jailbreak scene a few months ago, deleting his Twitter account as well – so this is definitely a surprise for everyone – including the Chronic Dev-Team who will be releasing GreenPois0n on Sunday.

For those who have doubts, LimeRa1n has already been confirmed by both the iPhone and Chronic Dev-Teams. We’ll bring you more details on this shortly. Give us your reaction to the news.