squeezelite-esp32/components/spotify/cspot/bell/external/nanopb/LICENSE.txt

Copyright (c) 2011 Petteri Aimonen <jpa at nanopb.mail.kapsi.fi>

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:

1. 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.

2. Altered source versions must be plainly marked as such, and 
   must not be misrepresented as being the original software.

3. This notice may not be removed or altered from any source 
   distribution.