There are many free and open-source online store systems on the market. Here, I will introduce the top 10 best ones. Each system has its own strengths and weaknesses, and caters to slightly different user groups.
1. Magento
Just look at Magento’s client list and you’ll know how outstanding this platform is. Samsung, The North Face, Stussy, and Nespresso are all their clients. With over 30,000 stores already using their system, it is the fastest-growing online store system in the world. Magento has an Enterprise Edition, which is paid. However, the Community Edition for developers is open-source and free.
2. osCommerce
osCommerce is a system based on the GPL license. It is very easy to use and has a very high adoption rate, with over 220,000 stores using this system. It also supports plugins, both free and paid.
3. OpenCart
OpenCart is not only good-looking but also highly extensible. You can create an unlimited number of categories, products, and it supports multi-currency, multi-language……
4. Spree Commerce
Spree is an open-source e-commerce platform based on Ruby on Rails. You can use Spree’s extension system to customize your online store. It supports over 50 payment methods, single-page checkout, and more.
5. PrestaShop
PrestaShop is a professional e-commerce solution that you can download, install, and use for free. It features a fully functional back office.
6. VirtueMart
VirtueMart is designed to work with Joomla. It is a very clean online store system that has already been downloaded over 2.5 million times.
7. Zen Cart 
Zen Cart is famously easy to use. It comes with built-in features like email marketing management, coupons, and gift vouchers. You can use various plugins to customize your store.
8. SimpleCart JS 
SimpleCart (js) 2.0 doesn’t just support Paypal anymore. It now also supports Google Checkout. You can now add plus and minus buttons, a remove button in the shopping cart, and you can also rearrange items. No database required, no programming, no headaches. A 20KB javascript code handles everything.
9. Zeuscart
Zeuscart’s biggest feature is its user-friendly and attractive interface, unlike other dull open-source storefronts. It is designed for small to medium-sized online stores.
10. CubeCart
CubeCart integrates well with many systems and the customer interface looks very professional. CubeCart 3 is free, but CubeCart 4 is paid, costing 110 euros.