The Seventh Annual Bio-Ontologies Meeting Moat House Hotel, Glasgow, 30 July 2004.

The Annual Bio-Ontologies Meeting has now reached its seventh consecutive year, running as a special interest group (SIG) of the much larger ISMB conference. This year's meeting in Glasgow had approximately 100 attendees. Since the advent of the Gene Ontology, which coincided with the first Bio-Ontologies Meeting, we have seen a year-on-year strengthening of the field; bio-ontologies has moved from being dominated by computer science to be led by biological applications; discussion is less about 'what is an ontology?' and more about 'how to build an ontology which is fit for purpose?'. This strengthening of the field can be seen elsewhere. Both the main ISMB conference and this year's Pacific Symposium on Biocomputing (PSB) have seen a large number of submissions to their ontologies track. For the first time a selection of the papers from the SIG is being published in this issue of Comparative and Functional Genomics. We hope that this will complement the publications of the larger conferences, bringing to a wider audience the cutting edge research that characterizes the Bio-Ontologies SIG.