WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.

Braintree - An all-in-one solution to accept, process, and split payments in your mobile app or online - from small business to large enterprise.

Thirty Bees - Open e-commerce platform designed to work out of the box.

Razorpay - Payment gateway solution for India with robust, developer friendly API and simple economic pricing.

Squarify.io - Sync inventory between Square and Shopify.

PayPal - PayPal is the faster, safer way to pay online without sharing financial details, send and receive money or accept credit and debit cards as a seller