What do .gitignore files tell us about the inherent complexity of programming languages? This gist can be run on data from GitHub's own collection of gitignore templates, whose repository is at https://github.com/github/gitignore, and counts how many rules are present in the template for each programming language.

nrules.svg

nrules.tsv

plot.jl

#Plots a bar chart of the number of rules in GitHub's .gitignore templates by language
#
#Produces a plot in a file specified by plotfile

using Gadfly

plotfile = "nrules.svg"
fileformat = SVG #You can emit other formats, like PNG

io = IOBuffer(readall(`sh rulecounter.sh`))
t = readdlm(io)
draw(fileformat(plotfile, 12inch, 6inch),
    plot(x=t[:,2], y=t[:,1], Coord.Cartesian(ymin=0),Geom.bar,
    Guide.xlabel("Language"), Guide.title("Number of .gitignore rules"),
    Guide.ylabel(""), Theme(background_color=colorant"white", grid_color=colorant"white"))
)

rulecounter.sh

#!/bin/sh

#Path to the local copy of https://github.com/github/gitignore
REPO=../gitignore

for f in $REPO/*.gitignore; do
   nrules=`grep -v ^\# $f | sed '/^$/d;' | wc -l`
   basef=`basename $f | sed 's/.gitignore$//'`
   echo $nrules\\\t$basef
done | sort -nr

Hmm, Python projects seems to be simple although it has 50 rules!!

I don't think this is a measurement of the inherent complexity of each language as you put it (OK the top ones are unnecessarily complex) but more the complexity of what people decided to make with these languages. Python for instance is used for so many things that indeed the most generic .gitignore is very large. But PHP would be even worse if you put all Symfony, Joomla, Wordpress, CakePHP, etc. together into one generic file for use in any project.
Your idea is very clever though, don't get me wrong : It would be interesting to run these statistics against real code repositories and looking at their .gitignore file length to see how it really comes out in reality ! (Although this might also be subject to added complexity by each project's specific configuration and add-ons)

Since when is Joomla a programming language? This has nothing to do with programming language complexity and is a pretty poor metric when it comes to tooling complexity.

Visual Studio is big because it includes ignores for many of its most common plugins, not to mention it supports a ton of the other languages on this list.