redsn0w 0.9.6 b4 Jailbreak iPhone iPad iPod Touch iOS 4.2.1 " Downloads for Win and Mac are availlable"

iPhone Dev Team has just released redsn0w 0.9.6 b4 with an official support for iOS 4.2.1 final release. It has fixed some issues with Mobile substrate and comex’s patches. They had promised an update yesterday as stated

So when does all this 4.2.1 jailbreak action happen?  Well if you’re a JB developer or tinkerer, you’ve already probably used the redsn0w mentioned in our last post to jailbreak 4.2.1 and at least get SSH working.  But beyond that, there are still some last minute issues with MobileSubstrate and comex’s kernel patches that are being fixed.  We’ll tweet and post a blog update when it’s all available (we hate to give ETAs, but barring any unforeseen problems, probably later today).

For details, you can check earlier update about iOS 4.2.1 Jailbreak and unlock.
Supported Devices for Untethered Jailbreak:

• iPhone 3GS Old Bootrom
• iPhone 3G
• iPod Touch 2G Non MC Models

Supported Devices for Tethered Jailbreak:

• iPhone 4
• iPhone 3GS New Bootrom
• iPad
• iPod Touch 4G
• iPod Touch 3G
• iPod Touch 2G MC Models

Download redsn0w 0.9.6 b4 for Windows [Official Link] [Mirror Link]
Download redsn0w 0.9.6 b4 for MAC [Official Link] [Mirror Link]