The license of the Irrlicht Engine is based on the zlib/libpng license, only the name and the authors name have been replaced. Even though this license does not require you to mention that you are using the Irrlicht Engine in your product, an acknowledgement would be highly appreciated.
The Irrlicht Engine is based in part on the work of the Independent JPEG Group. This means that if you use the Irrlicht Engine in your product, you must acknowledge somewhere in your documentation that you’ve used the IJG code, unless of course you recompile the engine without support for JPEG images. It would also be nice to mention that you use the Irrlicht Engine, the zlib and libpng. See the README files in the jpeglib and the zlib for further informations.
The Irrlicht Engine License
Copyright © 2002-2010 Nikolaus Gebhardt
This software is provided ‘as-is’, without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
- The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
- Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
- This notice may not be removed or altered from any source distribution.