Significant advances have been made in the knowledge base and practical options for improving thermophilic anaerobic digestion over the past 10 to 15 years. Today, more options exist that promise to enhance the degree of stabilization achieved and finished product quality in new and retrofitted existing processes. In parallel, the body of knowledge regarding pathogen inactivation in these systems has also been advanced, well beyond that available at the time that the 40 CFR Part 503 regulations were promulgated. This paper summarizes recent work with thermophilic anaerobic systems. This paper is a literature review and comparison of recent publications and work from a number of sources.