Original part textures belong to Squad / Deported B.V, used with permission:

Kerbal Space Program © Deported B.V.
Explodium Breathing Engines was created under Deported B.V.'s "Game Content Usage Rules"
using assets from Kerbal Space Program. It is not endorsed by Deported B.V. and does not
reflect the views or opinions of Deported B.V. or anyone officially involved in producing
or managing Kerbal Space Program. As such, it does not contribute to the official narrative
of the fictional universe, if applicable.

Also:
http://forum.kerbalspaceprogram.com/index.php?/topic/154851-add-on-posting-rules-march-8-2017/

8. Legal boundaries 
You may not decompile, modify or distribute any of the .dll files or other files KSP comes
with beyond content of the GameData folder. Follow the EULA. For assemblies, you may only
use exposed public or protected members of classes, and you may not examine the code within any member. 

Remaining content licensed as follows:

MIT License

Copyright (c) 2017 Gordon Fecyk

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
