The SNOMED CT Expression Constraint Language is a formal language for defining bounded sets of clinical meanings represented by either precoordinated or postcoordinated expressions.

Status

SNOMED CT expression constraint language version 2.1 has been published at http://snomed.org/ecl. 

Implementations

SNOMED International is aware of the following implementations of the SNOMED CT Expression Constraint Language:

• Snowstorm - SNOMED International Terminology Server (via REST API) - https://github.com/IHTSDO/snowstorm
  • Provides API for the SNOMED International public browser (See "Expression Constraint Queries" tab) - https://browser.ihtsdotools.org/
• SNOMED International SNOMED CT Query Service - https://github.com/IHTSDO/snomed-query-service
• CSIRO Ontoserver Expression Constraints - https://ontoserver.csiro.au/shrimp/ecl.html (help)
• ECL Syntax Parser - https://github.com/hsolbrig/SNOMEDCTParser
• Hermes:  https://GitHub.com/wardle/hermes 

• PHAST's FHIR Terminology server STS -  https://topaze.phast.fr/resources-server/api/fhir

  • Available 24x7 for testing, through CSIRO's VS tool -  https://ontoserver.csiro.au/vstool/

• Slang - http://slang.snomedic.com:8080/yats/ 
• SnoLyze - https://github.com/slaverman/SnoLyze (ECL v1.2)
• Snomedizer: https://github.com/ramses-antibiotics/snomedizer
• Snow Owl
  • Terminology Server (via REST API) - https://github.com/IHTSDO/snow-owl
    
  • ECL 2.1 - https://github.com/b2ihealthcare/snow-owl 
• SNQuery - http://snquery.veratech.es/
• Terminz - https://terminz.azurewebsites.net/fhir
• termMed’s termSpace - http://demo.termspace.com/ and https://termmed.atlassian.net/wiki/display/TSD/Creating+queries
• West Coast Informatics (WCI) SNOMED Terminology Server - https://snomed.terminology.tools/terminology-ui/index.html

If you know of additional ECL implementations, please contact info@snomed.org with details.