Google has officially released the Jelly Bean source code, merging it into the current Android Open Source Project (AOSP) codebase, which lets anyone download and tinker with the Android operating system.
Making the announcement of the release of android-4.1.1_r1 on Google Groups, Jean-Baptiste Queru stated that proprietary binaries are available for Nexus 7 and Galaxy Nexus, with those for Nexus S and Xoom planned to follow. The Nexus 7 tablet will come with Jelly Bean out of the box.
Now the source code is available custom ROM makers will be able to produce new ROM's for a wide variety of devices. Also hobbyists, enthusiasts, and researchers can now go ahead with developing custom builds.
If you do want to experiment then it is worth knowing that the requirements for Jelly Bean are the same as for ICS - minimum 16GB of RAM and 5 or 6 hours compile time on a fast machine.
Perhaps this is the reason the Jelly Bean statue on Google's front lawn melted in the heat recently - processor overload.