Following the installation steps in the website of the plugin, I got stuck. It talks about a Lua Interpreter, which after researching a bit I found (LuaBinaries), but I cannot seem to understand their installation instructions...
As it is now, I can create a new Lua Project and lua files, and even have the new perspective "Lua Profiler". However, when I try to open a newly created .lua file in a newly created lua project, Eclipse pops up all sorts of errors, every time a different one.
Would somebody be able to please help me install the whole Lua for Eclipse plug in?
I didn't go into the detail because I thought that maybe somebody was familiar with the situation.
Anyway, I found a solution to my problem. I changed the plugin (to LunarEclipse), installed an extra plugin (DLTK), and compiled the interpreter with the new instructions. Now it is all working correctly.
If an admin reads this thread, feel fee to close / move / delete it.