Always on

Workflow automation platform with a self-hostable server and an embeddable builder that a SaaS product can place inside its own app.

Rust web framework for building HTTP servers and web applications, with routing, middleware, WebSocket support and an async runtime.

TypeScript-first Node.js web framework for web apps and API servers, with ORM, validation, mail and queues in the core distribution.

Asynchronous HTTP client and server library for Python, built on asyncio, with a web server and a client session API.

Open-source proof-of-work CAPTCHA widget and server verification libraries, with a paid self-hosted server (Sentinel) and a hosted service (Cloud).

Java content management system for websites, intranets and portals, published under the Apache License.

Full-stack meta-framework for building Angular applications and websites, with Vite builds and Nitro server integrations.

Open-source web server for modern operating systems, extended by loadable modules.

Java suite of enterprise business applications for ERP, CRM and e-commerce, built on an entity engine, a service engine and a widget-based UI.

Application performance monitoring system for distributed systems, microservices and container-based architectures.

Apache Struts is an open-source MVC framework for building Java web applications.

Java servlet and JSP container, an open source implementation of the Jakarta Servlet, Pages, Expression Language, WebSocket, Annotations and Authentication specifications.

Component-based Java web framework that keeps behavior in Java classes and markup in plain HTML.

Open-source GraphQL server for Node.js that runs as an add-on to new or existing Node.js apps, including Express, Fastify and AWS Lambda.

Open source low-code platform for building internal tools, admin panels and dashboards.

Open-source backend platform with authentication, databases, storage, functions and messaging, available as Appwrite Cloud or self-hosted with Docker.

Multi-model database for documents, graphs and key-value data, queried with the AQL query language.

Cross-platform, open-source framework for building web apps and services with .NET and C#.

Web framework for content-driven websites that prerenders pages to static HTML and can render routes on demand.

Open-source authentication and authorization server and portal that adds multi-factor authentication and single sign-on in front of web applications.

Self-hosted, open source identity provider with OIDC, SAML, LDAP and proxy authentication.

Rust HTTP routing and request-handling library focused on ergonomics and modularity.

Web UI framework for building interactive web apps with C# and Razor components, shipped as part of ASP.NET Core.

Python library for interactive plots and data applications that render in web browsers.

Dashboard UI for Bull and BullMQ job queues, mounted into an existing Node server or run as a standalone CLI or Docker image.

Fast all-in-one JavaScript and TypeScript runtime that also ships a package manager, test runner and bundler as one executable.

Self-hosted platform as a service that deploys apps and one-click services to Docker containers behind nginx with automatic HTTPS.

Document generator that fills Word, Excel, OpenDocument and PowerPoint templates with JSON data and exports PDF and other formats.

Open-source identity and access management and single sign-on platform with a web admin console.

Open-source distributed storage system that serves object, block and file interfaces from one cluster built on commodity hardware.

Kubernetes controller that issues and renews X.509 TLS certificates for workloads in a Kubernetes or OpenShift cluster.

Column-oriented SQL database management system for analytical queries, available as open-source server software and as a cloud service.

Distributed SQL database that runs as a cluster of nodes and keeps its data replicated across them.

Self-hosted web comment engine that adds threaded comments, voting and moderation to web pages through an embedded widget.

Open source Node.js server that handles OAuth and streams files from remote sources such as Google Drive and Dropbox into uploads made with Uppy.

Open-source platform for building data-driven web applications, with a GraphQL API, PostgreSQL and a React administration interface.

Linux control panel for managing web hosting, websites and servers on dedicated servers and VPS, with a free core and a paid CWPpro edition.

Open-source, self-hostable platform that deploys applications, databases and services to Docker containers on the user's own servers.

Proprietary web hosting control panel and server management software, sold as cPanel & WHM licenses for servers that host websites.

Python web framework for data-centric applications built on an explicit schema, with a query language and components called cubes.

Proprietary web hosting control panel for managing websites, email, DNS and databases on Linux servers, with a paid license per server.

Python web framework with an ORM, URL routing, templating, forms and an automatic admin interface.

Self-hosted platform as a service that runs on a single Linux server and deploys web apps pushed to it with git.

Java content management system with an admin console, REST and GraphQL APIs and multi-site management, distributed as a Docker image and as a managed cloud service.

Embedded headless CMS that runs inside a Nuxt or Next.js app, with a typed local API, a REST API and an admin at /admin.

Self-hosted server management panel that deploys apps, databases and templated services on servers the user runs, using Docker.

TypeScript web framework for building backend servers, optimized for Bun and also runnable on Node.js.

Full-stack TypeScript CMS built on Astro, with an admin panel, a REST API and a plugin system, that runs on Cloudflare or a Node.js server.

Backend framework for TypeScript and Go in which application code declares the infrastructure it uses, such as databases, Pub/Sub and cron jobs.

Hosting control panel for running websites, email, databases and backups across one or more Linux servers in a single cluster.

Open source edge and service proxy for cloud-native applications.

Open-source TypeScript e-commerce platform built on Node.js and PostgreSQL, with a GraphQL API and React storefront and admin.

File-based router for universal React Native apps that run on Android, iOS and the web, part of the open-source Expo platform.

Minimalist web framework for Node.js for building web applications and APIs.

TypeScript framework for building server-side Node.js applications, with dependency injection and an Express adapter.

Python web framework for building APIs from standard Python type hints, served by an ASGI server.

Node.js web framework for building HTTP APIs and web applications, with a plugin architecture and schema-based validation.

Java enterprise search server with a built-in crawler, an admin console and a search UI, built on OpenSearch.

Express-inspired web framework for Go, built on Fasthttp.

Open-source feature flag and remote config platform, available self-hosted or as a cloud service, with SDKs for web, mobile and server-side apps.

Open-source experience management and survey platform, self-hosted or offered as a hosted cloud service.

Python and JavaScript low-code web framework for building data-driven web applications, with a built-in admin interface, roles and permissions.

Reverse proxy that exposes services behind a NAT or firewall to the internet through a server with a public IP address, written in Go.

S3-compatible object storage server for self-hosted, geo-distributed deployments, written in Rust.

Go web framework with a Martini-like API for building web services, REST APIs and web applications.

Open-source error tracking platform that works with Sentry client SDKs, self-hosted or hosted by GlitchTip.

Go web and RPC framework with code generation from API definitions, built-in resilience components and the goctl command-line tool.

Plugin-first CMS with a Go backend, a React admin built on the Gutenberg block editor and optional Astro themes, backed by PostgreSQL.

Python package for building web interfaces and demos for machine learning models and Python functions.

Open source application for querying, visualizing, alerting on and exploring metrics, logs and traces.

Horizontally scalable log aggregation system that indexes log labels rather than the text of log lines.

Open-source e-commerce platform built on ASP.NET Core and MongoDB, with multi-store and multi-vendor support.

Open-core feature flagging, experimentation and product analytics platform, available self-hosted or as a cloud service, with SDKs for application code.

HTTP server framework for JavaScript runtimes, built on the Request, Response and Headers primitives of the web platform.

Server for storing, accessing and encrypting secrets, with an HTTP API, a CLI and a web interface, that applications can call for credentials and keys.

Open-source GraphQL server that generates a GraphQL API over existing databases and other data sources, with a hosted Hasura Cloud edition.

Open-source user infrastructure platform for authentication, teams, payments, email and analytics, with a managed cloud and a self-hostable server.

Open source web server for Unix-like systems, focused on security and a small footprint, with CGI, FastCGI and reverse proxy support.

WebSocket backend for Yjs documents that syncs changes between clients in real time, from the team behind Tiptap.

Web framework built on Web Standards that runs on any JavaScript runtime.

Scala library for typeful, functional and streaming HTTP servers and clients, built on FS2 and cats-effect.

Self-hosted system for building agents that watch the web and incoming events and take automated actions on the user's behalf.

Open-source payments orchestration platform that routes transactions across payment processors, with a vault, a control center and reconciliation, self-hosted or hosted by Juspay.

Workflow orchestration platform for durable functions with step retries, scheduling and flow control, run by applications through language SDKs and self-hostable as a single server.

Open-source backend for web and mobile apps with a client-side, real-time database, auth, permissions, storage and streams.

Image optimizer that serves images in any size and format from a URL, using sharp for raster images and svgo for SVG.

Open-source distributed tracing platform that collects, stores and shows traces from requests that cross services.

Open-source orchestration platform for data, AI and infrastructure workflows, defined in YAML and run on a server with a web UI.

Open source identity and access management server with OpenID Connect, OAuth 2.0 and SAML 2.0 support.

Multithreaded, Redis-compatible key-value database and cache server, a fork of Redis.

Open source API gateway, built on NGINX, that routes, secures and transforms traffic to APIs through plugins, with a Kong Konnect SaaS option.

Go framework for building HTTP and gRPC microservices, with application lifecycle, generated transports, middleware and configuration.

Kotlin framework for building asynchronous servers and HTTP clients, extended with plugins and engines.

Open-source backend server with a pre-built API, realtime notifications and data storage for web, mobile and IoT applications.

Open-source platform for tracing, evaluating and monitoring LLM applications, sent from application code through SDKs and OpenTelemetry.

Rust framework for building reactive web applications, client-side or full-stack with server rendering and server functions.

Self-hosted ecommerce platform whose Go backend, GoCommerce, serves the API and an admin panel for a separate SvelteKit storefront.

Web server from LiteSpeed Technologies, sold under paid licenses, that reads Apache configuration files and includes a WebAdmin console.

Config-first web framework that builds business apps and internal tools from YAML configuration, served by a Node.js server.

Magnolia is a Java digital experience platform for managing and delivering web content, with a Community Edition under GPLv3 and a licensed DX Core.

Open-source headless commerce platform for Node.js with commerce modules, an admin dashboard and REST store and admin APIs.

Open-source headless platform for building multi-vendor marketplaces, built on the Medusa commerce core.

Proprietary relational database management system from Microsoft, with Express, Standard and Enterprise editions.

Vector database for storing and searching embeddings, run as a Docker or Kubernetes server or as Milvus Lite, a Python library.

Document database server built on the document model, offered as a community edition and as commercial Enterprise editions.

Commercial publishing and blogging system from Six Apart that publishes static pages, dynamic pages or both from templates.

Messaging server that routes messages between applications and services by subject, with optional persistence through JetStream.

Native graph database server that stores nodes and relationships and is queried with the Cypher language.

Progressive Node.js framework for building efficient, scalable server-side applications with TypeScript.

React framework for building full-stack web applications, with routing, rendering and data fetching.

C-based HTTP web server with reverse proxy, content cache, load balancer and mail proxy features.

Web admin interface for managing Nginx reverse proxy hosts, distributed as a Docker image with free Let's Encrypt certificates.

Spreadsheet-style interface for building online databases on SQLite, PostgreSQL or an existing database, self-hosted with Docker or offered as NocoDB Cloud.

Browser-based flow editor and Node.js runtime for building event-driven applications that connect devices, services and data.

Open-source notification infrastructure with one API for sending messages across in-app inbox, email, SMS, push and chat channels, self-hostable or available as a cloud service.

Self-hostable HTTP publish-subscribe server that delivers published messages as push notifications to phones, desktops and browsers.

Vue-based framework for building server-rendered, static and hybrid websites and web apps.

File-based content module for Nuxt that queries Markdown, YAML, CSV and JSON files from a Vue application.

Go reverse proxy that adds OAuth 2.0 and OpenID Connect authentication in front of web applications.

OCaml framework for building client and server web and mobile applications as a single program.

Suite of web-based open source business apps, including a website builder and an e-commerce app.

Open-source usage metering and billing platform that ingests usage events and bills customers for the usage.

OpenID Certified OAuth 2.0 and OpenID Connect server that issues tokens and connects to an existing login and consent app.

Haskell library and command-line tool that converts documents between markup formats.

Open source backend for web and mobile apps that runs on Node.js, stores data in MongoDB or PostgreSQL, and can be mounted on an Express app.

TypeScript framework that runs inside a Next.js app and generates an admin panel, database schema and REST, GraphQL and local APIs from one config, used as a headless CMS or application backend.

Open-source administration and development tool for PostgreSQL, run as a desktop application or as a web application.

PostgreSQL connection pooler, load balancer and database sharder written in Rust.

FastCGI process manager for PHP, built as an optional SAPI in the PHP source tree.

Java and Scala web framework whose production build is a distribution that runs as a server process, with Twirl templates.

Process manager for Node.js and Bun applications that keeps them running, with a built-in load balancer.

Open-source Go backend shipped as a single executable, with an embedded SQLite database, realtime subscriptions, authentication and a dashboard.

Open source website analytics tool that uses no cookies, offered as a managed service on poeticmetric.com or self-hosted with Docker Compose.

Standalone web server that serves a RESTful API directly from a PostgreSQL database schema.

Product analytics platform with session replay, feature flags, experiments, error tracking and surveys, self-hosted from its code or run as PostHog Cloud.

Python workflow orchestration framework that runs flows on schedules, events or API calls, with a self-hostable server.

Vector search engine and vector database, run as a server with a REST and gRPC API, also offered as Qdrant Cloud.

Java framework for building cloud-native applications that run on the JVM or as native executables.

Vue.js framework with UI components and a CLI that builds single-page, server-rendered, static, PWA, mobile, desktop and browser extension apps.

Framework for web apps that resumes on the client instead of hydrating, with Qwik City for routing and server rendering.

Web application environment for Common Lisp, for personal websites and deployable applications.

Router for React whose framework mode adds server rendering, static pre-rendering and data loading for building full-stack web apps.

Distributed key/value store, an independent LGPL-licensed fork of Redis.

In-memory data store used as a cache, database and streaming engine, offered under source-available and open-source licenses.

Python library for building full-stack web apps, with the frontend compiled to React and the backend run as a Python server.

Full-stack web framework built on Web APIs that combines routing, data, UI and asset compilation in one stack.

Async web framework for Rust with typed routes, request guards and built-in form and JSON handling.

Ruby web application framework with an ORM, routing, ERB views, background jobs and built-in deployment tooling.

S3-compatible distributed object storage server written in Rust.

Asynchronous Python web framework with its own production-ready web server.

Distributed file system and S3-compatible object store, written in Go, shipped as one weed binary.

Application monitoring and error tracking platform, self-hosted or offered as Sentry SaaS.

Services framework for .NET that builds HTTP and message-based web services from typed request DTOs.

Open-source observability platform built on OpenTelemetry that covers logs, metrics, traces, alerts and dashboards.

Ruby DSL for building web applications with a small set of route definitions, run on a Rack server.

Commercial content management and digital experience platform from Sitecore, sold as an on-premises product and a cloud product.

Self-hosted realtime server written in Rust that serves Pusher-compatible WebSocket and HTTP APIs.

Schema-less search backend server written in Rust that indexes words against identifiers.

Open-source commerce platform built on Ruby on Rails, with a REST API, TypeScript SDKs and a Next.js storefront.

Java framework for building stand-alone Spring applications with an embedded web server and auto-configuration.

Lightweight ASGI framework and toolkit for building async web services in Python.

Open-core PDF editing and processing platform for self-hosted servers and a hosted service, with a REST API.

Python framework that turns scripts into interactive web apps for data work.

Open source user authentication server, Core, with frontend and backend SDKs, self-hosted or as a managed cloud service.

Multi-model database, built in Rust, that stores document, graph, relational and time-series data in one engine and can run embedded or as a server.

Svelte-based framework for building web applications with server rendering, prerendering and client-side rendering.

Coroutine-based PHP extension for concurrent networking and TCP, UDP, Unix socket, HTTP and WebSocket servers.

Open-source durable execution platform whose server runs workflows and retries failed steps, self-hosted or as Temporal Cloud.

Open-source distributed SQL database, MySQL compatible, that supports hybrid transactional and analytical workloads.

Express-like web framework for Node.js, written in TypeScript and published as native ESM.

Open-source low-code platform for building internal tools and dashboards on existing databases and APIs, self-hosted or as ToolJet Cloud.

Rust framework that renders full-stack web apps as HTML on the server, with client reactivity compiled from the same Rust code.

Python web framework and asynchronous networking library that runs its own HTTP server rather than WSGI.

Cloud-native application proxy and reverse proxy that discovers routes from container, orchestrator and file providers.

Python framework for semantic search, LLM pipelines and workflows, with an embeddings database, a web API and Docker images.

Open-source search server with an HTTP API that indexes collections of documents for instant search, self-hosted or as Typesense Cloud.

Open-source web and product analytics platform, self-hosted or offered as Umami Cloud.

Open-source user onboarding platform for in-app product tours, checklists and surveys.

BSD-licensed in-memory key-value datastore for caching, message queues and primary database use, forked from Redis.

Server-side Swift HTTP web framework for building backends, web apps, APIs and HTTP servers.

Open-source headless commerce framework built on Node.js and TypeScript, with a GraphQL API.

Time series database and monitoring solution that stores metrics pushed by applications and agents, with a Prometheus-compatible query API.

JavaScript toolkit for composing full stack applications and frameworks from Vite and Nitro primitives.

Caching HTTP reverse proxy, installed in front of any HTTP server to cache its responses, configured with the Vinyl Configuration Language (VCL).

Cloud-native, horizontally scalable distributed database system built around MySQL.

Documentation framework that builds Markdown and MDX sources into docs sites, powered by Vite.

JavaScript framework for building user interfaces on the web, with a reactive rendering system and optional server rendering.

Low-code platform for building web and hybrid mobile applications, offered as a cloud service and as an on-premise installation.

Command-line toolkit that builds websites and web apps from XML with XSLT stylesheets.

Web-based administration tool for Unix-like servers that configures system files and server applications such as Apache HTTP Server, BIND and MySQL.

Asynchronous, event-driven PHP framework for building network servers that handle HTTP, WebSocket and custom socket protocols.

Sync engine that keeps a client-side datastore of a web app in step with a Postgres database.