Author: Fredrik Ingvarson
System: PC with Windows 10
Language: Mathematica 10.3
Length of source code: 153 characters
Length of executable file: 2938 bytes. This executable file is a plain text file but with lots of wrappers and additional Mathmatica code for generating an executable "notebook" within the Mathematica language (called Wolfram Language today, I think). Such notebook file can also contain the resulting output from calculations. The output can be anything (numbers, text, graphics, ...). If one opens this executable in Mathematica, you will only see the single line of source code as in the file "submitted christmas tree challenge F Ingvarson.txt"
Instructions on how to run: Mathematica is required. Open the .nb file or copy and paste into an empty notebook and press shift+return to execute. That's it.