Android 4.3 test build is leaked fro Samsung Galaxy S4. This is not just a test build but it is one of the final builds. The release version will not add or remove any features from this build version.
Details of the Firmware
Country: Open Asia
Version: Android 4.3
Build date: Tue, 8 Oct 2013 23:29:05 +0000
Product Code: OLB
This rom is a full wipe one, so please make a backup before you flash this.
Remember this firmware is for I9505 not for I9500. So if you are going to try this make sure you have the proper device.
Read more and download the firmware from SamMobile