Version 2.4 of the Integrated Microbial Genomes data management system is now available from the Department of Energy’s Joint Genome Institute. IMG 2.4's content has been updated with new microbial genomes from the version 25 release of the National Center for Biotechnology Information Reference Sequence database. It contains a total of 3,637 genomes consisting of 818 bacterial, 50 archaeal, and 40 eukaryotic genomes; 2,042 viruses and bacterial phages; and 687 plasmids. Among these genomes, there are 3,334 finished and 303 draft genomes, of which 256 are genomes sequenced by DOE JGI. The IMG native controlled vocabulary of functional terms and pathways has been extended to 4,148 terms and 524 pathways, with 546,169 genes characterized using IMG terms. Functional annotation of genomes in IMG has been further enhanced through the computation of fused genes and by filling in various RNA genes missing from the original genome data sets. The next IMG update is scheduled for March 2008. Registration for September workshops on IMG, offered by JGI, is now open (click here).