The Livermore Prediction Center conducted the target collection and prediction submission processes for Critical Assessment of Protein Structure Prediction (CASP4) and Critical Assessment of Fully Automated Structure Prediction Methods (CAFASP2). We have also evaluated all the submitted predictions using criteria and methods developed during the course of three previous CASP experiments and preparation for CASP4. We present an overview of the implemented system. Particular attention is paid to newly developed evaluation techniques and data presentation schemes. With the rapid increase in CASP participation and in the number of submitted predictions, special emphasis is placed on methods allowing reliable pre-classification of submissions and on techniques useful in automated evaluation of predictions. We also present an overview of our website, including target structures, predictions, and their evaluations ( http://predictioncenter.llnl.gov). Proteins 2001;Suppl 5:13–21. © 2002 Wiley-Liss, Inc.