Over the past 25 years, enormous breakthroughs have been made in understanding protein folding mechanisms. We have now reached an exciting stage, with consensuses beginning to emerge that combine both theoretical and experimental approaches. In addition, new fields have emerged and burgeoned, including in vivo folding and the study of protein misfolding diseases. In today's post-genomic world, understanding protein folding has never been more important and the topic has wide-ranging impact in fields from structural biology to materials science.