"Took about four hours, with notepad to write the map generator script and photoshop for the legend. I downloaded an .asc (ascii) file [with pop density, about] 30 million records. Converted the huge 200 MB file to a smaller file with this php script in which 30 catogories were used instead of exact numbers. [...] Convert the file to an image. For that I used the PHP GD Library [and script. And finally] Added the legend and some color using photoshop. It's the first time I tried creating a map using programming language only, instead of ArcGIS or tools like that. I was surprised how little lines of code were needed in order to generate such a map. If someone has suggestions for improvement let me know ;-)"
18 January 2014
World Population Density ~ People per Square Km
Lovely hi-res worldmap of people per square kilometer by daysleeperrr posted on Reddit MapPorn. The comments are also illustrative. And author's note...