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Unified Medical Language System® (UMLS®)


graphic of the MetamorphoSys startup screen

MetamorphoSys is a free tool distributed with the UMLS. It is used to create a custom Metathesaurus subset and is needed to install the most current UMLS Knowledge Sources.

MetamorphoSys is multi-platform software. It is tested and supported on the following operating systems:

  • Sun Solaris 9
  • Windows XP, NT, Vista, and 2000
  • Linux, all releases are fully tested under Red Hat Workstation Linux; other Linux releases may work equally well.
  • Macintosh OS X (Leopard, Snow Leopard)

Note: For Macintosh systems MetamorphoSys requires Java 1.6.

MetamorphoSys demands a powerful computer with a great deal of space. Minimum standards are expected to change slightly with each release. The most recent minimum standards are available in the UMLS Reference Manual.

For the most recent minimum recommended standards are:

  • A CPU of 2GHz or higher
  • 2 GB of RAM, preferably more
  • 30 GB of free disk space

Last Reviewed: July 29, 2016