WooCommerce is an open source e-commerce plugin for WordPress. It is designed for small to large-sized online merchants using WordPress. WooCommerce was first developed by WordPress theme developer WooThemes, who hired Mike Jolley and James Koster, developers at Jigowatt, to work on a fork of Jigoshop that became WooCommerce. In August 2014, WooCommerce powered 381,187 sites (or 17.77% of e-commerce sites online). WooCommerce has attracted significant popularity because the base product, in addition to many extensions and plugins, is free and open source. In addition, there are thousands of paid add-ons for fixed prices. Many Premium Themes now offer capability with WooCommerce as well as plugins that make a theme framework compatible.