Plugin integration. A miRMaid plugin is implemented as an isolated MVC slice (an 'Engine' in the Ruby on Rails framework). The plugin defines its own data models and the relationships between these models. The integration (model and resource relationships) between the miRMaid core framework and the plugin is configured inside the plugin. The core framework provides hooks where a plugin can register itself. In the example above, the miR2Disease plugin defines two data models, M2dDisease and M2dDiseaseLink, where only the M2dDiseaseLink integrates directly with the core framework (a 'one-many' relationship with the Mature data model and resource). The effect of this integration is that M2dDiseaseLink objects are connected to Mature objects and that these relationships can be queried directly through the data models or by using RESTful resource URLs.