NCI EVS and the National Center for Biomedical Ontology (NCBO) both use the LexGrid model for storing ontological and terminological data, and also on Lex server and Lex APIs implementations that are essentially identical. NCBO developed the BioPortal to support a variety of user interactions with the NCBO's repository of ontologies. Through NCBO BioPortal ontologies can be up and downloaded, browsed, searched and so on. NCI EVS needed a similar interface for caCORE EVS 4.x, and adopted BioPortal as the basis of the NCI BioPortal variant.

NCI BioPortal does not support all the features of the NCBO BioPortal: for example up-loading ontologies and meta data about ontologies is not supported. On the other hand the NCI variant supports search of meta thesaurus data and searching by semantic features present in certain ontologies such as roles and annotation properties and their range values.

Due to time pressure it was not possible to support the NCI and NCBO needs for the portal in a single code base. However two closely related variants are undesirable. Accordingly NCI, NCBO, Mayo Clinic and the U.K. Cancer Grid have joined forces to undertake an effort to develop and distribute a portal that will be open, site neutral, extensible and robust. Called the Terminology Open Portal (TOP), the initiative is only just getting started and welcomes other participants. Currently plans call for development of service oriented architecture resources, software development kits and other resources that will facilitate interaction with terminology and ontology repositories.