Introduction:

Jailbreaking is a process that allows iPhone and iPod Touch users to run unofficial code on their devices bypassing Apple’s official distribution mechanism, the App Store. Once jailbroken, iPhone users are able to download many applications previously unavailable through the App Store via unofficial installers such as Cydia, Rock App, Icy, and Installer. Cydia is popular with users whilst Rock App has a small catalog of mainly paid apps. Icy and Installer are officially unsupported by their developers and rarely used. Cydia founder Jay Freeman estimates that 8.5% of all iPods and iPhones are jailbroken.[1] A jailbroken iPhone or iPod Touch is still able to use and update apps downloaded and purchased from Apple’s official App Store.

Jailbreaking is distinct from SIM unlocking, which is the process by which a mobile device is made compatible with telephone networks with which it was not specifically licensed to be used. Jailbreaking, while not illegal, gives a user the ability to install cracked and pirated apps, which is illegal. Jailbreaking, according to Apple, voids Apple’s warranty on the device, although this is quickly remedied by restoring the device in iTunes.

Instructions:

1. Ensure you have the latest version of iTunes (Version 9.0.2 at the time of writing) installed
   • Download iTunes for Windows
   • Download iTunes for Mac
2. Ensure that your iPhone or iPod Touch is on Software Version 3.1.2
   • You can check this by opening iTunes, clicking on your device on the left and looking at the version line on the right as shown below
     
   • If your device is on a lower version then click the ‘Check for Update‘ button
   • If your device is on a higher version then check this site for a newer article!
3. Download Blackra1n by geohot
   • Download blackra1n for Windows
   • Download blackra1n for Mac
4. Launch Blackra1n
   • In Windows, double click blackra1n.exe
   • In Mac, extract blackra1n.zip and then double click the extracted blackra1n application
   • In both cases a window similar to the below one will appear
     
5. Click make it ra1n button
6. The application will now perform the jailbreak process and reboot your iPhone/iPod Touch.  Be patient and ignore anything iTunes tells you for a few minutes.
7. When your iPhone/iPod Touch has rebooted the process is complete
8. You will now have a new app on your iPhone/iPod Touch screen called blackra1n.  Launch this app and install the package installer of your choice.