Add OpenTripPlanner, a free software multimodal route planner.

README.md

@@ -795,6 +795,7 @@ See also [awesome-gis](https://github.com/sshuair/awesome-gis).
   - [OpenStretMap Automated Navigation and Directions (OsmAnd)](https://osmand.net/) - Offline mobile maps and navigation app [for Android](https://f-droid.org/packages/net.osmand.plus/) and iOS clients with further online capabilities. ([Source Code](https://github.com/osmandapp)) `Java/Objective-C++` `GPL-3.0/MIT`
   - [OSM Contributor](https://wiki.openstreetmap.org/wiki/OSM_Contributor_Mapping_Tool) - Easy to learn Android application for individual users to add or edit data in OpenStreetMap's database. ([Source Code](https://github.com/jawg/osm-contributor)) `GPL-3.0` `Java`
   - [StreetComplete](https://wiki.openstreetmap.org/wiki/StreetComplete) - Gamified interface that offers "quests" to correct or complete data in OpenStreetMap's database. ([Source Code](https://github.com/westnordost/StreetComplete/)) `Java` `GPL-3.0`
+- [OpenTripPlanner](https://www.opentripplanner.org/) - Multimodal trip planning software based on OpenStreetMap data and consuming published GTFS-formatted data to suggest routes using local public transit systems. ([Source Code](https://github.com/opentripplanner/OpenTripPlanner)) `LGPL-3.0` `Java/JavaScript`
 - [Orion](https://github.com/LINKIWI/orion-web) - Powerful OwnTracks API-compliant location data visualization frontend for the web. ([Demo](https://linkiwi.github.io/orion-web/)) `MIT` `Python/Nodejs`
 - [OwnTracks Recorder](https://github.com/owntracks/recorder) `⚠` - Store and access data published by [OwnTracks](http://owntracks.org/) location tracking apps. `GPL-2.0` `C`/`Lua`
 - [TileServer-GL](http://tileserver.org/) - Map server made for vector tiles able to render into raster tiles with MapBox GL Native engine on the server side. ([Demo](https://maps.klokantech.com/), [Source Code](https://github.com/klokantech/tileserver-gl)) `BSD-2-Clause` `Nodejs`