Usually we can read a lot on how an .svg file was created by opening it with a text editor.
In the example linked to in the question the .svg file tells us the following in it's header:
<!-- Created with Inkscape (http://www.inkscape.org/) -->
But there is much more we can find out from the xml tags which define the objects in an SVG file:
style="font-size:48px;font-variant:normal;font-stretch:normal;text-align:center;text-anchor:middle;fill:#eeeeec;font-family:Trebuchet MS;-inkscape-font-specification:Trebuchet MS"
The xml tags will also have information on colours used, styles of borders or fill patterns. It is then very easy to reproduce the original drawing or modify it to our personal needs.
Much easier than reading the file in a text editor is opening it in the application used to create it to read the object's properties there.