[danielhep]

I am involved with the OpenTripPlanner project, which is a Java trip planning application that also uses the RAPTOR algorithm! It’s used in cities all over the world, with the biggest deployment being ENTUR’s in Norway, which covers the entire country. I believe all trip planning apps in Norway use this deployment.

It supports many features and has a very active developer community.

[franga2000]

OTP is such a wonderful project! It's my go-to example of open source in government and it's so much more than a trip planning engine. For the country-wide transit app I'm working on (ok, it's a small country, but still), we use it as the database as well. We convert everything into GTFS(-RT), throw it into OTP, then have a fairly thin API layer that queries it via GraphQL and returns JSON for our app [0].

I also have to say the code is far more elegant and readable than what I expected from a 15 year old Java project. I had to fix a bug once and I figured it would take me at least a few hours to get my bearings in a codebase that size, but I managed to wrap my head around the core routing logic and fix the bug in an hour or so. The A* implementation for non-transit routing is such a good example of "enterprise code" done right.

[0] a shitty diagram: https://gitlab.com/derp-si/ojpp-docs/-/wikis/oJPP-infra/diag...