With over 35,000 GitHub stars and 460 contributors, Medusa is the headless commerce framework that gives development teams full ownership of their e-commerce backend without license fees, per-transaction charges, or revenue sharing. The modular architecture ships over 18 domain modules covering products, collections, categories, inventory, pricing, carts, orders, payments, fulfillment, promotions, customers, users, API keys, and stock locations, each independently usable and replaceable. REST and GraphQL APIs expose every commerce operation to any frontend framework — official starters exist for Next.js with community options for Nuxt, Remix, and Gatsby. The React-based admin dashboard provides out-of-the-box order management, product maintenance, promotions configuration, B2B accounts, and multi-warehouse inventory, extensible via the Admin SDK for custom views and workflows. The workflow engine orchestrates long-running commerce processes like checkout, fulfillment, and returns with compensating transactions for reliability. Over 200 official and community plugins integrate Stripe, PayPal, Klarna, Algolia, Meilisearch, SendGrid, Mailchimp, Contentful, Sanity, and Klaviyo. Native multi-region and multi-currency support handles tax-inclusive pricing, region-specific payment and fulfillment providers, and localized storefronts from a single backend. Enterprises including Viessmann, Makro PRO, and INSPIRED Pet Nutrition run Medusa in production. Self-hosting deploys via Docker or directly on Node.js with PostgreSQL and Redis. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

GrandNode lets you run one shop, a dozen regional storefronts, or a full marketplace from a single installation, with a back office for every role involved. Each store gets its own domain, theme, currencies, languages, and settings, and a store manager panel limits staff to the catalog, orders, and customers of their own store. Outside sellers join through a vendor panel where they manage their own products and orders. The catalog handles attributes and combinations, bundles, grouped items, downloads, date-based reservations, and auctions. B2B selling adds customer groups, tier prices, sales employees, and approvals. Checkout accepts payments through plugins such as Stripe Checkout, Braintree, and cash on delivery, with shipping by fixed rate, weight, or pickup point and tax rules by country, state, or zip code. Marketing tools include coupon codes, discount rules, loyalty points, gift vouchers, customer segments, newsletter campaigns, and push notifications. Clean URLs, sitemaps, and structured data with price and availability help search engines read your products. Pages, blog posts, news, and sliders cover content, and a REST API serves headless storefronts and ERP or CRM integrations. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

Kill Bill handles the complete subscription billing lifecycle from plan definition through invoice generation to payment collection across any gateway, with 15 years of Fortune 500 production use and 5,600+ GitHub stars behind it. Plans, trials, add-ons, and pricing tiers live in a versioned XML catalog that propagates changes without code deploys. The multi-phase subscription engine manages trial periods, promotional discounts, evergreen billing, usage-based metering, and hybrid pricing models with automatic proration on plan upgrades and downgrades. Automated invoice generation calculates charges, applies credits and adjustments, and triggers payment collection through pluggable gateways including Stripe, Adyen, Braintree, PayPal, and CyberSource. The Java plugin framework extends every billing domain with custom logic for tax calculation via Avalara AvaTax or Vertex, fraud detection through Accertify or Feedzai, and ERP integration without modifying the core. The Kaui admin dashboard gives finance and operations teams account management, subscription controls, invoice views, payment configuration, billing timeline visualization, MRR tracking, advanced search, and full audit history with object-level change tracking. Multi-tenancy isolates billing data across thousands of brands with tenant-specific catalogs, payment configs, and RBAC policies. REST APIs expose every operation with webhook notifications for downstream integration. Deploys via Docker Compose on MySQL or PostgreSQL. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

An online store you own end to end: OpenCart bundles the storefront, product catalog, checkout, and admin panel into one self-hosted install with no monthly software fee. Products take options and attributes, and master products can spawn variants that override price, SKU, and stock level. Unlimited categories, filters, reviews and ratings, coupons, specials, and reward points help shoppers find items and return for more. Guests and registered customers can check out by bank transfer, cheque or money order, or cash on delivery; subscription plans with trial periods handle recurring orders, and more gateways and carriers install from the extension marketplace. Shipping rules include flat-rate, free, per-item, pickup, and weight-based options. Tax classes, geo zones, and multiple currencies with automatic rate updates support selling abroad. One admin interface manages several stores, each with its own theme, layout, and language settings, and user groups control who may edit what. A built-in blog adds topics, articles, and comments with anti-spam rules, and language packs cover more than 40 languages, right-to-left scripts included. Sales, tax, shipping, product, and customer reports, campaign tracking, an affiliate program, bulk customer mail, GDPR export and removal tools, and downloadable digital goods round out the business side. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.