WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.
Gumroad - An all-in-one solution to sell your work and grow your audience.
PrestaShop - Create your online store with PrestaShop's free shopping cart software. Build an ecommerce website for free and start selling online with hundreds of powerful features.
Easy Digital Downloads - Easy Digital Downloads is a complete eCommerce solution for WordPress.
Shopify - Shopify is a powerful ecommerce platform that includes everything you need to create an online store and sell online. Try it free for 14 days.
Ko-fi - Ko-fi offers a friendly way for content creators to get paid for their work.