This directory contains libraries that are used by the game:

osx/ contains a script for download and building required libraries on OS X.
source/ contains bundled source, when the game requires a specific library
    version that may not be available in package managers.
win32/ contains headers and precompiled static libs for Windows builds.

  osx/build-osx-libs.sh
    MIT

  osx/patches
    see license of applicable library

  source/cxxtest-4.4
    LGPL v3 - see COPYING

  source/fcollada
    MIT (see src/FCollada/Copyright.txt)

  source/nvtt
    MIT - see src/NVIDIA_Texture_Tools_LICENSE.txt

  source/glad
    Apache-2.0 / (WTFPL OR CC0-1.0) 

  source/spidermonkey
    MPL / GPL / LGPL

  source/valgrind
    BSD

  win32/boost
    Boost Software License

  win32/enet
    MIT

  win32/fmt
    MIT

  win32/gloox
    GPL v3

  win32/iconv
    LGPL v2.0 (or later)

  win32/icu
    MIT-X11 - see license.html

  win32/libcurl
    MIT

  win32/libpng
    libpng license

  win32/libsodium
    ISC license

  win32/libxml2
    MIT

  win32/miniupnpc
    BSD

  win32/openal
    LGPL v2.0 (or later)

  win32/opengl
    MIT

  win32/sdl2
    zlib license

  win32/vorbis
    BSD

  win32/zlib
    zlib license