nttd
Copyright 2026 deepsaia

This product includes software developed as part of the nttd project.
Licensed under the Apache License, Version 2.0 (see LICENSE).

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Third-party software and content
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nttd does not bundle or redistribute OpenTTD. It launches a separately installed
OpenTTD binary as a child process and communicates with it over TCP (the admin
network protocol). Users must install OpenTTD themselves.

OpenTTD is licensed under the GNU General Public License version 2.0.
    https://github.com/OpenTTD/OpenTTD
    https://www.openttd.org/

Base graphics, sound, and music sets (OpenGFX, OpenSFX, OpenMSX) are separate
works with their own licenses, obtained by the user through OpenTTD's Online
Content service. nttd does not redistribute them.

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Note on the GameScript
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ottd_config/game/nttd-gs/ contains a GameScript written in Squirrel. Unlike the
rest of this project, it does not run as a separate process: OpenTTD loads it
into its own embedded Squirrel VM, where it extends GSController and calls
OpenTTD's GS* script API in-process.

This project licenses that GameScript under Apache-2.0 along with everything
else. Two consequences are recorded here deliberately:

  1. Because the GameScript runs inside OpenTTD and against its GPL-2.0 API,
     whether it constitutes a derivative work of OpenTTD is a question this
     project does not attempt to settle. Most published GameScripts on OpenTTD's
     BaNaNaS content service are GPL-2.0.

  2. Apache-2.0 is one-way incompatible with GPL-2.0. An Apache-2.0 GameScript
     therefore cannot be contributed upstream to OpenTTD or published to
     BaNaNaS without relicensing.

This is a deliberate, revisitable choice, not an oversight.
