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.

BTCPay Server processes Bitcoin payments with zero transaction fees, zero monthly costs, and zero third-party custody of your funds. Payments settle directly from customer to your wallet through a full Bitcoin node that provides cryptographic proof of receipt without trusting any intermediary. Lightning Network integration through LND, Core Lightning, or Eclair enables sub-second confirmation at sub-cent fees, with Ride The Lightning providing web-based node management within BTCPay itself. The Point of Sale app creates storefronts with product catalogs, tipping, and QR code displays for physical retail, events, or web embeds. Hardware wallet support through BTCPay Vault connects Ledger, Trezor, and ColdCard for transaction signing, keeping private keys in cold storage while running a hot payment interface. Multi-tenant architecture allows multiple stores on one instance, each with isolated wallets, Lightning nodes, and user permissions. The Greenfield REST API exposes every function programmatically for headless operation, automated invoicing, and custom integrations. E-commerce connectors for WooCommerce, Shopify, Magento, and PrestaShop plug in alongside Zapier for workflow automation. Optional Tor hidden services expose the instance as an onion address for censorship resistance. The official Docker Compose stack handles Nginx reverse proxy, Let's Encrypt TLS, and optional Tor configuration on a dedicated RepoCloud VPS with guaranteed CPU, RAM, and SSD. MIT licensed.

Used by Tailwind Labs and recognized as an official GitHub funding partner, Polar is the open-source billing infrastructure that lets developers ship production-ready monetization in hours instead of weeks. Meter tokens, API calls, agent runs, GPU seconds, and storage with event-level precision, then compose usage billing with subscriptions, seats, credits, trials, and discounts into whatever pricing model your product requires. As Merchant of Record, Polar handles sales tax, VAT, chargebacks, receipts, and regulatory compliance across all supported countries so you receive clean payouts without building tax infrastructure. Integrate via the full REST API with official SDKs for JavaScript, Python, PHP, and Go, plus framework adapters for Next.js, Astro, Remix, SvelteKit, and Laravel enabling checkout integration in minutes. Automatically deliver benefits upon purchase including GitHub repository access, Discord roles, license keys, file downloads, and meter credits through configurable automation rules. The built-in customer portal provides subscription management, payment method updates, invoice history, and benefit access with full white-label branding. Monitor revenue, costs, and margins through real-time analytics dashboards showing the unit economics every AI startup needs to scale. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache License 2.0 licensed.

Hyperswitch from Juspay delivers the most comprehensive open-source payment orchestration stack available — a Rust-built platform that connects to Stripe, Adyen, Braintree, Worldpay, Checkout.com, Cybersource, and 120+ payment processors through a single API integration. Intelligent routing drives each transaction to the processor with the highest predicted authorization rate using rule-based, volume-based, and machine learning algorithms, while seamless failover and automatic retries recover revenue from declined transactions using 30+ parameters including decline codes, card BIN, transaction size, and region. The PCI-compliant card vault stores payment methods securely in a dedicated service separate from the main application server, and the reconciliation engine automates 2-way and 3-way matching with backdated support, staggered scheduling, and customizable audit-ready outputs. The Control Center dashboard provides visual workflow builders for routing rules, payment analytics, and operations management. Cost observability tools drill into scheme, interchange, and acquirer fees to detect anomalies and optimize processing costs. The modular architecture allows deploying individual components — routing, retries, vaulting, observability, or the full suite — without vendor lock-in. The web client SDK collects payment information with prebuilt UI components and supports WooCommerce integration. Deploy via Docker Compose with the app server, control center, card vault, and 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.

Vendure is a headless ecommerce framework where TypeScript plugins extend every aspect of commerce without forking the core, backed by 8,200+ GitHub stars and powering stores processing over 10,000 daily transactions. Two distinct GraphQL APIs serve different audiences: the Shop API powers storefronts while the Admin API handles back-office operations, both introspectable and type-safe through Apollo Server. NestJS modules with Vendure decorators inject services, modify schemas, subscribe to events, and add dashboard components, making extensibility a first-class concern rather than an afterthought. The React admin dashboard built with TailwindCSS and Shadcn UI provides order fulfillment workflows, catalog management, tiered pricing, dynamic promotion rules with side-effect hooks for free gift injection, and role-based access control across 14+ languages. Multi-channel support runs D2C, B2B, marketplace, and omnichannel from a single instance with channel-specific products, pricing, currencies, sellers, and permissions. Asset management handles images, videos, and documents with pluggable backends including AWS S3 and Minio, plus built-in image transformation via the AssetServerPlugin. Custom fields propagate automatically into GraphQL schemas and admin forms on every core entity. A dedicated worker process handles search indexing, email dispatch, and integration jobs with independent horizontal scaling. Deploys on PostgreSQL, MySQL, or MariaDB. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPLv3 licensed.

Hi.Events is an alternative to Eventbrite, Tickettailor, and Dice.fm, eliminating per-ticket platform fees entirely when self-hosted. Event organizers create fully brandable event pages supporting paid, free, donation, and tiered ticket types with recurring and multi-date scheduling, sold-out waitlists that automatically release tickets when spots open, and product add-ons with category organization. Stripe Connect integration processes payments directly to the organizer's bank account with instant payouts, while offline payment methods support cash and invoice scenarios. Promo codes offer fixed or percentage discounts with usage limits, expiry dates, and promo-gated hidden tickets for VIP access. QR code check-in enables fast door scanning with multiple check-in lists, scan logs, and real-time attendance tracking across entry points. Custom checkout questions collect attendee information beyond standard fields, with advanced search, filtering, CSV and XLSX export, full and partial refunds, and bulk attendee messaging. The analytics dashboard tracks daily sales, revenue, tax breakdowns, product performance, and promo code usage with exportable reports, while affiliate tracking assigns custom codes to promoters with tracked sales data. Multi-user roles control organizer permissions, automatic invoicing generates receipts, and the REST API ships with interactive OpenAPI documentation. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

Backed by 23,000+ GitHub stars and trusted by global brands processing millions of orders, Saleor delivers the open-source headless commerce API that replaces monolithic ecommerce platforms with a composable, GraphQL-native architecture where APIs are the only way to interact with the system. The core engine built on Python and Django handles catalog management, order processing, payment orchestration, inventory tracking, and fulfillment workflows while remaining completely decoupled from any frontend technology. Native multichannel support enables per-channel control of pricing, currencies, warehouses, product availability, and payment methods, managing Instagram, Amazon, regional websites, and retail POS from a single backend. The extensibility layer provides 160+ webhooks spanning synchronous payment callbacks, asynchronous event notifications via Google Cloud Pub/Sub and AWS SQS, and subscription queries that shape webhook payloads to deliver only the data your services need. Dashboard UI Extensions offer 45+ mount points for embedding custom interfaces via iframes without forking, while the Apps system allows building payment gateways, PIM integrations, loyalty programs, and discount logic in any language. The React-based administration dashboard provides product management, order processing, customer segmentation, and analytics with multi-language and multi-currency support. OIDC integration connects existing identity providers for single sign-on across the merchant organization. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. BSD 3-Clause licensed.

Tracking over 50,000 fleet vehicles across production deployments, Fleetbase delivers a modular logistics operating system where each module—Fleet-Ops, Storefront, Pallet, and Ledger—works independently yet shares a unified data layer that eliminates middleware between ordering, dispatch, warehousing, and accounting. The Fleet-Ops core handles real-time driver tracking through a SocketCluster-based WebSocket event bus, interactive map-based dispatch with both directed and ad-hoc driver assignment, configurable order workflows with custom rules, automation triggers, and activity flows, plus a Kanban-style order board for visual pipeline management. Service zones let dispatchers define geographic operating areas, while proof-of-delivery capture and route optimization close the last-mile loop. The Storefront module provides headless e-commerce with products, carts, and checkout that feed directly into dispatch queues, and the Ledger module records invoices and financial journal entries across all operations. The Navigator driver app—also AGPL-3.0 licensed and fully white-label—delivers turn-by-turn navigation, live order communication, and fault reporting to drivers in the field. The extension architecture pairs backend Laravel Composer packages with frontend Ember Engine modules, enabling third-party developers to build first-class platform extensions without forking. A RESTful API with full documentation, webhook delivery via Redis-backed queues, and push notification support through APNs and FCM round out the integration surface. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

Roughly 43% of all websites and over 60% of the CMS market run on WordPress - the GPL-licensed platform that scales from a personal blog to publishing operations and WooCommerce stores. The Gutenberg block editor composes pages from reusable blocks, and full site editing extends block control to headers, footers, and templates; tens of thousands of plugins and themes cover essentially every capability a site might need, from SEO and caching to membership and e-commerce. WordPress 7.0 "Armstrong" marks the platform's biggest structural update since Gutenberg itself: a React-based DataViews admin replaces the legacy list tables with instant filtering, a provider-agnostic AI Client API ships with connectors for OpenAI, Anthropic, and Google, media processing moves into the browser via WebAssembly, and a universal Font Library manages typography across block, hybrid, and classic themes with local hosting for GDPR compliance. New Breadcrumbs, Icons, and lightbox Gallery blocks reduce plugin dependence, and server-side PHP block registration simplifies development. The REST API and WP-CLI make it automatable end to end. Self-hosting is what WordPress was designed for: your content, database, plugin choices, and upgrade schedule stay entirely under your control, free of wordpress.com plan limits.

Spree Commerce provides a complete headless ecommerce backend where products, orders, payments, and promotions are managed through typed REST APIs with OpenAPI 3.0 specs and TypeScript SDKs providing autocomplete and type safety. Fifteen years of production history and 15,600+ GitHub stars back a mature ecosystem that ships a production-ready Next.js 16 storefront built with React 19 and Tailwind CSS 4, including multi-region URL routing and Stripe payments supporting Apple Pay, Google Pay, Klarna, and Affirm. Sales Channels model distinct contexts from a single instance: DTC storefronts, wholesale portals, mobile apps, and point-of-sale terminals, each with its own catalog, pricing, and checkout flow. The rules-based promotion engine supports coupon codes, multi-condition discounts, gift cards, and digital product fulfillment. Multi-warehouse inventory tracks stock across locations in real time with reservations and advanced order routing that splits shipments across fulfillment centers. B2B capabilities include customer-specific price lists, storefront access gating, wholesale portals with approval workflows, and quick order forms. The admin dashboard built with Tailwind CSS provides role-based permissions, product management, order processing with refunds, and scaffold generators for custom pages. BSD 3-Clause licensed with zero platform or transaction fees. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console.

Magento's extensibility without PHP, Shopify's polish without the platform tax: EverShop is the TypeScript-first e-commerce platform built on that promise. Architected as a modular monolith on Node.js, it organizes every piece of business logic - catalog, checkout, customers, your custom extensions - into modules that plug in without touching core code, extended through a disciplined set of mechanisms: registry processors for transforming data across modules, hooks that wrap function calls, async event subscribers (product created, order placed), and route middleware. The storefront and the fully-featured admin panel are both React with server-side rendering and hydration, giving fast first paint and SEO-friendly pages, while a typed GraphQL API (plus REST endpoints) serves exactly the data each view needs - the same API that powers headless and PWA builds. Standard commerce is covered: product management with variants and attributes, category navigation, cart and checkout, order and customer management, coupons, and a theme system built on React components and Tailwind for deep storefront customization. PostgreSQL is the default database, deployment is Docker-friendly with near-zero configuration, and the GPL-3.0 license means the entire stack - types, resolvers, and checkout flow included - is yours to read and modify.

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.