Background: main biomedical information retrieval systems are based on controlled vocabularies and most specifically on terminologies or ontologies (T/O). These classification structures allow indexing, coding, annotating different kind of documents. Many T/O have been created for different purposes and it became a problem for finding specific concepts in the multitude of existing nomenclatures. The NCBO (National Center for Biomedical Ontologies) BioPortal and the CISMeF (Catalogue et Index des Sites Médicaux de langue Française) HeTOP projects have been developed to tackle this issue.

Objective: the present work consists in comparing both portals.

Methods: we hereby are proposing a set of criteria to compare bio-ontologies portals in terms of goals, features, technologies and usability.

Results: BioPortal and HeTOP have been compared based on the given criteria. While both portals are designed to store and make T/O available to the community and are sharing many basic features, they differ on several points mainly because of their basic purposes.

Conclusion: thanks to the comparison criteria, we can assume that a merge between BioPortal and HeTOP is possible in terms of functionalities. The main difficulties will be about merging the data repositories and applying different policies on T/O content.