NiCE is stored in a Subversion repository at its Sourceforge page:
https://svn.code.sf.net/p/niceproject/code
The repository has the following structure:
The repository allows anonymous access to the general public. Write access is only available to members of the NiCE Development Team at Oak Ridge National Laboratory at this time.
Wiki: Compiling NiCE From Scratch
Wiki: Enabling Real-time Simulation Updates with NiCEUpdater