Due to the behaviour of people in the past, access to the source code online has been restricted.
You may download the entirety of the latest publically released stable version from DragonPrime.
You may then work with that code within the restrictions of its license.
Hopefully this will help put an end to actions like the following:
Releasing code which they do not own without permission.
Removing valid copyright information from code and replacing it.
Removing portions of the code required to be kept intact by licensing.
Claiming copyright of items which they did not create.