Absinthe is a jailbreaking software that is available for Windows, Mac and Linux, can be used to jailbreak [untethered] all iOs devices running firmware 5.1.1. It can also be used to jailbreak iPad 2 on iOS 5.0.1 and iPhone 4S on 5.0/5.0.1. It was released by hacking dream team consisting of many popular hackers from iPhone dev team and chronic dev team inlcuding @p0sixninja, @musclenerd, @Pod2G, @planetbeing, @saurik and many others.
Just download latest version of Absinthe from links below, plug your device into computer and run Absinthe. Follow the on-screen instructions to jailbreak your device.