The FAQs are provided by the Vocabulary Knowledge Center.
The vocabularies are different in a number of areas including origins, format, license, and coverage. To see all the differences look at this comparison.
The NCI EVS project makes the NCI Metathesaurus available for download in RRF format, along with the supporting files needed to load this in UMLS's MetamorphoSys, through the download center. Some of the vocabularies within the NCI Metathesaurus are subject to license restrictions, so all users who wish to download these files must have a license from the UMLS and provide their credentials before downloading. For those users who download the NCI Metathesaurus from the NCI EVS download site, the procedure for submitting license information has changed.
The UMLS recently (January, 2011) changed the requirements for providing credentials and NCI EVS has been required to update their download site to comply. It is no longer necessary to provide your UMLS license number for downloading the NCI Metathesaurus; instead you will be prompted for the username and password for your UMLS account. This information is sent securely to a UMLS license server which will provide us with an acceptance or rejection. If the login is accepted you will be allowed to download the NCI Metathesaurus.
NCI EVS has no control of the actual username or password and does not have the ability to create UMLS accounts. The account and license is free and available from NLM.
If your question was not answered on this page, please start a new thread in the Vocabulary Knowledge Center forum for this terminology.