Let’s face it: being a geoscientist and writing code goes hand in hand in recent times. Most programs have their own code editor like MatLab with its m-file generator or R with its handy version of RStudio. But when it comes to webmapping and direct code writing in an open environment you are mostly sticked to a certain editor which has some syntax higlighting and maybe a syntax checker like Notepad++, kate, textwrangler or Sublime.
The term GIS is very closely associated with the layer concept, as a standard GIS will allow you to work in various levels and their proper representation. When you talk about GIS, you will might need to visualize this layer principle. Here is a template for such a visualization you can use under the CC license: