Symfony está distribuida bajo una licencia MIT (Massachusetts Institute Technology). Según Wikipedia:
"Es una licencia gratuita permisiva de software, lo que significa que tiene pequeñas restricciones en su reutilización. Se permite reutilizar el software tanto para ser software libre como para ser software no libre, permitiendo no liberar los cambios realizados al programa original. Dichos cambios pueden llevar licencias BSD, GPL u otras compatibles".
La nota de copyright y los derechos han de incluirse en todas las copias o partes sustanciales del software. Es la única condición que invalida la licencia.
Los derechos son muy amplios: usar, copiar, modificar, integrar con otro software, publicar, sublicenciar o vender copias del Software.
La licencia Symfony es la siguiente:
Copyright (c) 2004-2015 Fabien Potencier
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.
