Shopify is described as 'Create your online store with Shopify and start selling today' and is an website in the Business & Commerce category. There are more than 100 alternatives to Shopify, not only websites but also apps for a variety of platforms, including Self-Hosted solutions, SaaS, Windows and Linux. The best alternative is Thirty Bees, which is both free and Open Source. Other great sites and apps similar to Shopify are PrestaShop (Free, Open Source), Shopping Cart Elite (Paid), Squarespace (Paid) and ISPmanager (Paid).
Payhip is an e-commerce platform that enables anyone to sell ebooks directly to their fans and followers using just a link. You can simply upload your product, enter the price and start selling on Twitter, Facebook or your own website.
CubeCart is a hugely popular and very established open source eCommerce solution. A fantastic shopping cart which is easy to install, with a committed group of forum members eager to answer any CubeCart question.
Yo!Kart is a multi-vendor eCommerce platform to build online stores like Amazon, Ebay & Etsy. It is a fully customizable & scalable ecommerce marketplace software that allows business owners to make changes as per their requirements.