Google announced the new version of Android OS 4.1 Jelly Bean two days ago. All the Android fans all over the world are waiting for the new update. Before the official updates start arriving, some lucky Galaxy S III owners have a chance to try this.
If you are a user of international version of Samsung Galaxy S III i9300 then you can test is now. If your Galaxy S III is not the international version, don’t try this to save the trouble. Because the ROM is not official, there are some things not working such as Wi-Fi, Bluetooth, Audio, Camera and NFC. You may not access, ADB, Touchscreen, Hardware Acceleration, Notification LED, Cellular Rado (But No Audio so no Calls), Physical Buttons, SMS, Accelerometer, Charging, or some more features. If you are willing to try this, you must ignore the stuff not working. Before trying this read the instructions carefully and user feedback at the source link below.
Checkout How To Install Custom ROM In Samsung Galaxy S III
Source: XDA Developers