Represent medical knowledge schemes such as RxNORM, SNOMED and LOINC in standard SKOS, add in JSON-LD, the graph-aware flavor of JSON, and either open source Fuseki/Jena or MongoDB and you have what you need for a service to represent, compare and reason over medical knowledge.
To get started, just git clone this repository and follow the instructions for either a Fuseki/Jena or MongoDB based service.
Eating our own: we host an SKS at schemes.caregraf.info.