Of course I still use Perl

I'm running Debian Stable (7.x, Wheezy, 7.4 to be exact) on amd64.

Count all Debian packages by their implementation language (I know, not the most efficient way):

% ( for tag in `debtags tagcat | grep '^Tag: implemented-in::' | sed 's/^Tag: //'`; do
    echo -e `debtags search $tag | wc -l` "\t" $tag
  done ) | sort -nr
4439     implemented-in::c
3258     implemented-in::perl
1840     implemented-in::c++
1063     implemented-in::python
304      implemented-in::java
289      implemented-in::ruby
214      implemented-in::ocaml
199      implemented-in::lisp
194      implemented-in::shell
137      implemented-in::php
118      implemented-in::TODO
97       implemented-in::r
92       implemented-in::haskell
79       implemented-in::c-sharp
62       implemented-in::objc
55       implemented-in::tcl
47       implemented-in::fortran
41       implemented-in::vala
41       implemented-in::scheme
37       implemented-in::lua
30       implemented-in::ecmascript
28       implemented-in::ada
2        implemented-in::ml
0        implemented-in::pike
0        implemented-in::erlang

I wonder why no Go yet...

Let's exclude all Perl libraries (/^lib.+perl$/) from that Perl count:

% debtags search implemented-in::perl | perl -ne 'next if /^lib\S+-perl - /; print' | wc -l
558

Now for Python (/^python-$/):

% debtags search implemented-in::python | perl -ne 'next if /^python-/; print' | wc -l
669

And Ruby:

% debtags search implemented-in::ruby | perl -ne 'next if /^ruby-|^lib\S+-ruby[\d.]* -/; print' | wc -l
85

Lastly, for OCaml (I included OCaml because it's supposed to be easy to integrate with C code/libraries and produces binaries that has fast startup time, appropriate for creating Unix tools):

% debtags search implemented-in::ocaml | perl -ne 'next if /^lib\S+-ocaml(-dev)? -/; print' | wc -l
86