Twenty years ago, we had no such word as "biointerface." Now we use that word almost routinely to suggest surface-localized events between biological systems and solid surfaces (solids that vary in solidity from almost fluid to hard). To examine with a new perspective this burgeoning field, five facets of the biointerface will be explored. The five faces of the biointerface will be: temporally (and historically), spatially, molecularly, entrepreneurially and virtually (in computer space). Studies from our groups at the University of Washington and from others in the field will be presented. The talk will aim at defining the new field of the biointerface, relating it to "classical" surface science and highlighting opportunities.