OpenMTC is an IoT middleware consisting of gateway and backend functionalities. The gateway hosts protocol adapters that interconnects various devices and decodes device specific information. Therefore OpenMTC fulfills most of the concepts and functionalities that are described in the FIWARE IoT architecture. OpenMTC enables interworking between FIWARE and oneM2M interfaces, allowing for resources synchronization with the Orion Context Broker using the NGSI-9/NGSI-10 protocol. The FIWARE interworking service can be deployed on OpenMTC gateways as well as on the OpenMTC backend. OpenMTC is accessible as Generic Enabler in the FIWARE Catalogue as an alternative implementation of the existing IoT Backend and IDAS (IoT Agent) Generic Enablers. A detailed documentation about the OpenMTC Orion Context Broker Application can be found at the OpenMTC Github Repository.