ArangoDB is a multi-model database that combines graph, vector, document, key-value and search data in one system, with a single query language (AQL). It is used for knowledge graphs and AI applications that query connected enterprise data, among other things. Alongside the self-managed software, the vendor offers an Enterprise Edition with features such as high availability, disaster recovery, role-based access control and elastic scaling. You run the software yourself, on your own servers or in a cloud of your choice.
The source code of the self-managed version is licensed by ArangoDB, Inc. under the Business Source License 1.1, which according to the licence text itself is not open source. Internal production use, copying, modification and non-production use are permitted; a commercial offering that lets third parties create or manage databases is not. Each version converts to Apache 2.0 four years after release. Because you host it yourself, you decide where your data is stored, including within the EU. Use outside the terms requires a commercial licence from the vendor.