This paper provides an overview of a system for the automatic composition of publications. The system first composes nested hierarchies of contents, then applies layout engines at branch points in the hierarchies to explore layout options, and finally selects the best overall options for the finished publications. Although the system has been developed as a general platform for automated publishing, this paper describes its application to the composition and layout of a magazine-like publication for social content from Facebook. The composition process works by assembling design fragments that have been populated with text and images from the Facebook social network. The fragments constitute a design language for a publication. Each design fragment is a nested mutable sub-layout that has no specific size or shape until after it has been laid-out. The layout process balances the space requirements of the fragment’s internal contents with its external context in the publication. The mutability of sub-layouts requires that their layout options must be kept open until all the other contents that share the same space have been considered. Coping with large numbers of options is one of the greatest challenges in layout automation. Most existing layout methods work by rapidly elimination design options rather than by keeping options open. A further goal of this publishing system is to confirm that a custom publication can be generated quickly by the described methods. In general, the faster that publications can be created, the greater the opportunities for the technology.