SUMMARY: iMembrane is a homology-based method, which predicts a membrane protein's position within a lipid bilayer. It projects the results of coarse-grained molecular dynamics simulations onto any membrane protein structure or sequence provided by the user. iMembrane is simple to use and is currently the only computational method allowing the rapid prediction of a membrane protein's lipid bilayer insertion. Bilayer insertion data is essential in the accurate structural modelling of membrane proteins or the design of drugs that target them. AVAILABILITY: http://imembrane.info. iMembrane is available under a non-commercial open-source licence, upon request. CONTACT: kelm@stats.ox.ac.uk Supplementary informaton: Supplementary information is avail-able at Bioinformatics online and at http://www.stats.ox.ac.uk/proteins/resources.