When i download some of the applications that are set on the website to show us how it was made, i don't know how to see the code written. Every time i open the main lua file without the simulator, the graphic converter shows up. what is the graphic converter and how do we see the code?
Thank you.

Try opening the main.lua file from a code editor; like Eddie :)

Or right click -> Open With, pick a text or code editor, and select always open with.

It'l re associate the extension with that editor. For OSX I just use TextWrangler or TextMate.

For Windows Ultraedit is good enough - but there's definitely better out there.