The library is moving to a new system. The editing and the uploading of new texts will happen there, because there are no comrades enough to take care of two parallel archives.
The bookbuilder, which you are looking for, works on the beta too. So please point your browser at http://beta.theanarchistlibrary.org and proceed from there. The links are supposed to keep backward-compatibility. Please contact marco AT theanarchistlibrary.org if you encounter any problem.