title: Truck-Factor
url: http://mtov.github.io/Truck-Factor/
hash_url: 2c8d94b5bcf14c7ea7a09208f80241bf

<p>We calculate the Truck Factor for 133 popular GitHub applications, in  six languages: JavaScript (22 systems), Python (22 systems), Ruby (33 systems) , C/C++ (18 systems), Java (21 systems), and PHP (17 systems). We also used <a href="https://github.com/github/linguist">github/linguist</a> to discard non-source code files (e.g., documentation) and also third-party files.</p>

<p>To calculate the truck factor, we use a greedy heuristic: we consecutively remove the author with more authored files in a system, until more than 50% of the system's files are orphans (i.e., without author). We are considering that a system is in trouble if more than 50% of its files are orphans.</p>

<ul>
<li><p><strong>TF = 1</strong>: activeadmin/activeadmin, alexreisner/geocoder, atom/atom-shell, bjorn/tiled,
bumptech/glide, caskroom/homebrew-cask, celery/celery, celluloid/celluloid,
clojure/clojure, codemirror/CodeMirror, dropwizard/dropwizard, dropwizard/metrics, elasticsearch/logstash, erikhuda/thor, Eugeny/ajenti, getsentry/sentry, github/android, gruntjs/grunt, jadejs/jade, janl/mustache.js, jnicklas/capybara, jrburke/requirejs, justinfrench/formtastic, kivy/kivy, koush/ion,
kriswallsmith/assetic, Leaflet/Leaflet, less/less.js, mailpile/Mailpile, mbostock/d3,
meskyanichi/backup, mitchellh/vagrant, mitsuhiko/flask, mongoid/mongoid,
nate-parrott/Flashlight, netty/netty, nicolasgramlich/AndEngine, 
omab/django-social-auth, openframeworks/openFrameworks, paulasmuth/fnordmetric, phacility/phabricator, plataformatec/devise
powerline/powerline, puphpet/puphpet, pydata/pandas, ratchetphp/Ratchet,
ReactiveX/RxJava, sampsyo/beets, sandstorm-io/capnproto, sass/sass,
sebastianbergmann/phpunit, sferik/twitter, silexphp/Silex, sparklemotion/nokogiri,
sstephenson/sprockets, strongloop/express, substack/node-browserify,
ThinkUpLLC/ThinkUp, thoughtbot/factory_girl, thoughtbot/paperclip, wp-cli/wp-cli</p></li>
<li><p><strong>TF = 2</strong>: ajaxorg/ace, ansible/ansible, apache/cassandra, bbatsov/rubocop, bundler/bundler
bup/bup, composer/composer, cucumber/cucumber, divio/django-cms
driftyco/ionic, drupal/drupal, elasticsearch/elasticsearch, excilys/androidannotations, facebook/osquery, facebook/presto, FriendsOfPHP/PHP-CS-Fixer, github/linguist, haml/haml, Itseez/opencv, jashkenas/backbone, jekyll/jekyll, JohnLangford/vowpal_wabbit, jquery/jquery-ui
libgdx/libgdx, moment/moment, mozilla/pdf.js, mrdoob/three.js, prawnpdf/prawn
Respect/Validation, rg3/youtube-dl, SFTtech/openage, 
spring-projects/spring-framework, thinkaurelius/titan, thumbor/thumbor
WordPress/WordPress, xetorthio/jedis, yiisoft/yii2</p></li>
<li><p><strong>TF = 3</strong>: bitcoin/bitcoin, boto/boto, BVLC/caffe, gradle/gradle, ipython/ipython
jquery/jquery, meteor/meteor, Shopify/active_merchant, spotify/luigi</p></li>
<li><p><strong>TF = 4</strong>: chef/chef, cocos2d/cocos2d-x, emberjs/ember.js, iojs/io.js, ruby/ruby</p></li>
<li><p><strong>TF = 5</strong>: diaspora/diaspora, django/django, joomla/joomla-cms, resque/resque, TryGhost/Ghost</p></li>
<li><p><strong>TF = 6</strong>: puppetlabs/puppet, scikit-learn/scikit-learn</p></li>
<li><p><strong>TF = 7</strong>: rails/rails</p></li>
<li><p><strong>TF = 8</strong>: git/git ,JetBrains/intellij-community, Seldaek/monolog, v8/v8, webscalesql/webscalesql-5.6</p></li>
<li><p><strong>TF = 9</strong>: saltstack/salt</p></li>
<li><p><strong>TF = 10</strong>: fog/fog</p></li>
<li><p><strong>TF = 11</strong>: odoo/odoo, php/php-src</p></li>
<li><p><strong>TF = 12</strong>: android/platform_frameworks_base</p></li>
<li><p><strong>TF = 21</strong>: fzaninotto/Faker</p></li>
<li><p><strong>TF = 90</strong>: torvalds/linux</p></li>
<li><p><strong>TF = 159</strong>: Homebrew/homebrew</p></li>
</ul>

<p>Our results are summarized as follows:</p>

<ul>
<li>
<p>Most systems have a small truck factor: </p>

<ul>
<li>61 systems have TF=1 (46%), including systems like mbostock/d3, and clojure/clojure.</li>
<li>37 systems have TF=2 (28%), including systems like cucumber/cucumber, mrdoob/three.js, mozilla/pdf.js, spring-projects/spring-framework.</li>
</ul>
</li>
<li><p>The two systems with the highest Truck Factor are torvalds/linux (TF = 90) and Homebrew/homebrew (TF = 159).  </p></li>
</ul>