diff --git a/bus-factor.js b/bus-factor.js
new file mode 100644
index 0000000..d606cff
--- /dev/null
+++ b/bus-factor.js
@@ -0,0 +1,49 @@
+// USAGE:
+// $> node bus-factor.js clojure/clojurescript
+// 68.95% – swannodette – (209226)
+// 3.76% – brentonashworth – (11412)
+// 3.68% – richhickey – (11181)
+// 3.48% – stuarthalloway – (10561)
+// 2.23% – michalmarczyk – (6756)
+// 1.63% – bobby – (4950)
+// 1.54% – bostonou – (4682)
+// 1.50% – EricThorsen – (4550)
+// 1.30% – fogus – (3939)
+// 1.15% – Chouser – (3487)
+
+const fetch = require('node-fetch');
+const _ = require('lodash');
+const moment = require('moment');
+const process = require('process');
+const url = `https://api.github.com/repos/${process.argv[2]}/stats/contributors`;
+
+function contributions(user) {
+  // deletions are more valuable, because they imply refactorings and/or
+  // better understanding of the codebase
+  return user.weeks.reduce((accu, n) => {
+    const timestamp = parseInt(n.w);
+    const week = moment.unix(timestamp);
+    const reference = moment().subtract(1, 'year');
+    const diff = moment.duration(week.diff(reference)).months();
+    const coeff = diff < 1 ? 0.5 : Math.exp(diff / 4);
+    return accu + (n.a + n.c + n.d * 2) * coeff;
+  }, 0);
+}
+
+fetch(url)
+  .then((res) => res.json())
+  .then((json) => {
+    const stats = json.map((user) => ({
+      login: user.author.login,
+      contributions: contributions(user),
+    }));
+    const sorted = _.sortBy(stats, 'contributions');
+    const sum = _.sum(sorted.map(x => x.contributions));
+    const biggest = _.reverse(_.takeRight(sorted, 10));
+    biggest.map(x => {
+      x.percent = (x.contributions * 100.0 / sum).toFixed(2);
+      return x;
+    }).forEach(x => {
+      console.log(`${x.percent}% – ${x.login} – (${x.contributions})`);
+    });
+  });