From The Apple Wiki
Original author(s)winocm
Preview release
Pre-alpha / 12 December 2011; 11 years ago
Written inC, Objective-C
Operating systemWindows, Linux
Available inEnglish
TypeJailbreak Utility

opensn0w is an open source jailbreaking tool, intended to provide much of the functionality that is in redsn0w, be more developer friendly, and encourage more cooperation and sharing in the community. It is currently a work in progress. All code is available on GitHub [Archived 2015-06-26 at the Wayback Machine]. You can tether-boot an iPhone 4 on iOS 7.x and Apple TV (2nd generation) 6.x with this.