Julian Parkhill is Head of Pathogen Genomics and Director of Sequencing at the Sanger Institute. His research is at the forefront of genome sequence analysis and bioinformatics. He has delivered reference genomes of some of the most important pathogens in an open access form and provided simple tools for their analysis. He has worked directly with scientists and clinical groups to throw light onto key aspects of the biology of these agents. His studies have focused mainly on bacteria but he has contributed to important work on both eukaryotic parasites and viruses. He is now incorporating the latest sequencing technologies into studies on microbial population structure, transcriptomics and microbial communities.