Underscore.js Developer(s) Jeremy Ashkenas Initial release October 28, 2009 (2009-10-28)[1] Stable release 1.8.3 / April 2, 2015 (2015-04-02) Repository https://github.com/jashkenas/underscore Development status Active Written in JavaScript Size 5.7 KB production 52 KB development Type JavaScript library License MIT Website underscorejs.org