Andrew Trevorrow wrote the cross-platform GUI code using wxWidgets. Much thanks to Julian Smart and all the other wxWidgets developers.
Chris Rowett wrote a lot of the canvas code (see wxcanvas.cpp). Chris also wrote all of Breakout.lua, large parts of CanvasDemo.lua, and various parts of the gplus/cplus modules.
Tom Rokicki wrote the cube solving code in Rubik'sCube.lua.
Glu uses the cute_sound library from the cute_headers project to play sounds, so much thanks to Randy Gaul.
Glu's scripting capabilities are thanks to the generosity and efforts of Roberto Ierusalimschy and all the other Lua developers. Here is the Lua copyright notice:
Copyright © 1994–2020 Lua.org, PUC-Rio.
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.