I am working and I want to make my own gui in lua. I've only done gui in java before, and I don't want to work with external libraries or anything.
It would be very hard to do GUI in Lua without external libraries, since Lua comes only with basic libraries. Every GUI framework for Lua comes as external library. You have a lot to choose from - if you come from Java background and are comfortable with Swing, try and look at LuaJava [1]. If you want to use GTK, try lgi [2], if you worked with Qt, try lqt [3] which mimics the C++ API.
I could work with xml, or something else, just not any other language or external library. If you could help that would be great.