Its time for developers and ROM creators to celebrate. Well, not actually but it happens that Samsung has just made available the source code of the Galaxy S3 Android ROM for download. However, TouchWiz still remains behind the firewall and is still closed source.
You can download the source from this link:
This Galaxy S3 source code released by Samsung is meant for Verizon device owners only and it consists pf the kernel source code and various other stock components that were modified by Samsung as per its requirements and were released under GPL.