The Haxe toolkit is free, open source software. Different parts of the toolkit are released under different licenses:
The Haxe compiler is released under the GNU General Public License version 2 or any later version. This ensures the Haxe compiler will remain free and open source.
The license requires the users distributing modified versions of the Haxe compiler to also distribute the source code, licensed under the same license. Therefore distributing proprietary/non-free versions of the Haxe compiler is not allowed.
The license of the compiler does not affect the license of your own source code. If you use Haxe and the Haxe compiler it is not required that you release your work (including output generated by the Haxe compiler) under a free open source software license.
Since Haxe 3, the Haxe Standard Library has been licensed under a MIT style license, which does not require the notices to be reproduced anywhere outside of the actual library code.
Copyright (C)2005-2016 Haxe Foundation 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.
The Neko virtual machine is available under the MIT License. This allows you to embed it in proprietary software.
The Neko runtime libraries (ndll) and other tools bundled in a default Neko installation are released under various open source licenses as described in https://github.com/HaxeFoundation/neko/blob/master/LICENSE