Ultrasn0w unlock software
Ultrasn0w was first launched as an unlock tool for the iPhone with 3.0 iOS firmware.
The ultrasn0w was released in the June of 2009 and was developed and released by the famous hacker group Dev Team.
You can see the Youtube announcement of the unlock in the video bellow. It was made by the member of the Dev Team known by his nickname @Musclenerd
What is Ultrasn0w?
Ultrasn0w is the software tool which is used for the carrier unlocking for your iPhone. To be able to use the ultrasn0w unlock you must first jailbreak your iPhone. The jailbreak and unlock will depend on the model and the firmware version of your iPhone.