iOS 9 Untethered Jailbreak Released for iPhone, iPad and iPod Touch
The jailbreak tool is currently available for Windows only, but an OS X version will likely be available for Mac users in the future.
Pangu is compatible with all iPhone, iPad and iPod touch models on iOS 9 - iOS 9.0.2:
Jailbreaking enables iPhone, iPad and iPod touch users to install unapproved third-party apps, tweaks, mods, custom themes, utilities and other content — called "packages" — from Cydia, an unofficial App Store for jailbroken devices.
Jailbreaking has been around since the early days of iPhone OS 1.0, years before the software was renamed iOS, allowing users to have features such as custom wallpapers, quick reply and Notification Center widgets long before Apple made those official.
As noted by iPhone Hacks, Cydia Substrate, an underlying framework for jailbreak tweaks, now supports iOS 9. Cydia developers will be required to update their jailbreak tweaks for compatibility with iOS 9 or later. The blog has shared a running list of iOS 9 compatible jailbreak tweaks.
While jailbreaking allows users to further customize and enhance their iOS devices beyond the limits that Apple imposes, modifying your device's software violates your End User License Agreement (EULA) and voids your warranties — although the device can generally be restored to factory default settings through iTunes.
It is highly recommended that you back up your data through iTunes before attempting to jailbreak your device, as you may encounter various issues or errors that could result in data loss or corruption. Pangu offers step-by-step instructions on how to use the iOS 9 untethered jailbreak on its website. Use the jailbreak at your own risk.