So, Lua scripting is possible in many emulators, such as VBA-RR, FCEUX, Bizhawk, and many more. Due to this, many people (including myself) have created cool scripts to enhance or add on to games. I encourage you all to try and make your own scripts, Lua is fairly easy to get into and widely used for applications that aren’t just these emulators (Garry’s Mod comes to mind!)
Here are some things made using Lua + Emulators
(I made this! 
)
If you make anything or have any questions, feel free to ask! Make sure to share your creations.
Here are some links to get started on Lua scripting in-general and for emulators:
https://www.lua.org/start.html
http://tasvideos.org/LuaScripting.html