Hi,
You've found a website that explains how to use a great game engine that is free!
That page describes how to use a Lua extension library that is not supported by GG. That "other game engine" supports a large number of extension libraries, in addition to it's own powerful libraries. It's well documented, and there are lots of tutorials.
AFAIK, GG supports only the standard libraries(string, table, math, i/o, etc) and, of course, it's own functions.
Windows 10 Home 64-bit / Intel i5 2500k @ 4.4Ghz + Asetek 510LC / Intel DP67DE / Intel 530 Series 240GB SSD / 16GB Kingston KVR 1333 / XFX Radeon R9 380X / Corsair TX 650 / Antec 300
