OpenTripPlanner

OpenTripPlanner is a self‑hostable server that builds a transportation network from OpenStreetMap and GTFS feeds, then calculates itineraries that combine scheduled public transit with walking, cycling, bike‑share and ride‑hailing options. The Java‑based core runs on any platform with a JVM and exposes GraphQL and other web APIs, allowing custom web, mobile or JavaScript clients to retrieve route suggestions in real time. Real‑time updates and alerts are incorporated so the planner can reflect service disruptions and changes instantly.

The project is open source under LGPL‑3.0, free to use without subscription, and has been actively developed for over sixteen years. It is packaged as a shaded JAR and also available as a Docker image, making deployment straightforward for transit agencies, startups, consultants and other organizations that need multimodal journey planning. Documentation, community chat and issue trackers provide support for developers extending or integrating the system.