GraphHopper

The library and optional server compute routes using OpenStreetMap data, delivering distance, travel time, turn‑by‑turn instructions and a range of road attributes for single or multi‑point queries. In addition to basic “A‑to‑B” routing, it supports map‑matching, isochrone generation, and mobile navigation, and can ingest other data sources beyond OSM. The engine is implemented in Java, can be embedded as a dependency or run as a standalone web service, and is released under the Apache‑2.0 license.

It is aimed at developers who need to integrate routing, navigation, or geographic analysis into applications such as delivery logistics, field service dispatch, outdoor recreation, or any system that requires fast, memory‑efficient path calculation. The project provides a public API, a web UI for interactive use, and documentation covering routing profiles, custom vehicle constraints, and optimization features.

Distinctive aspects include its focus on speed and low memory consumption, support for a wide variety of routing profiles (e.g., car, bike, scooter, hiking), and the ability to perform route optimization and analysis without external services. The software is self‑hostable, free to use, and maintained by an open community.