Apache TinkerPop Gremlin Traversal API

The Gremlin graph traversal language and API provide a functional, data-flow-based language for expressing complex graph queries and mutations. Gremlin steps include vertex/edge traversals (V, E, out, in, both, outE, inE), filtering (has, where, filter), transformation (map, flatMap, select, project), aggregation (groupCount, group, count, sum), and mutation steps (addV, addE, property, drop). Available as Java, Python, JavaScript, Go, .NET, and other language SDKs.