The serve command starts the cirrocumulus server for use in a shared server environment which can handle concurrent requests from multiple users. The server can optionally enforce permissions at the dataset level, in order to securely share datasets with collaborators. Additionally, annotations and sets are shared among all users authorized to view a dataset and are stored in a database. The server can be deployed on a cloud VM, an on-premise machine, or on Google App Engine. When deployed in App Engine, the server can be configured to be use Google Cloud Firestore as a database. On AWS, we recommend using DocumentDB. Please note that no datasets are available until you import a dataset into cirrocumulus.