Find the best open-source alternatives

A free open-source Ruby on Rails scoring server for cyber Capture the Flag competitions with dynamic hints and web-based challenge management.

A local-first API client and HTTP interceptor for building, testing, and mocking APIs directly in your browser or desktop.

A Node.js server and web client for creating synchronized video-watching channels with integrated chat.

An open-source Node.js implementation of the ArcGIS GeoServices REST API specification for serving geographic data.

A self-hosted server for sending push notifications via Matrix, compatible with Gotify's API.

A library for building high-performance custom human pose estimation applications with real-time inference and flexible model development.

An online mind mapping editor with native-like interaction, cloud sync, and instant sharing capabilities.

A modular, low-resource network honeypot that mimics services to detect breaches and alert on attacker interactions.

An X.509-based instant messaging server using ASN.1-defined protocols and DER serialization for secure, standards-compliant communication.

A lightweight and lightning-fast Java WebDriver client for test automation professionals.

Build interactive web visualizations with Python without HTML/JS knowledge, inspired by R's Shiny package.

A private, self-hosted Terraform/OpenTofu registry for modules and providers with a web dashboard and RBAC.

A fast, lightweight terminal user interface for managing Docker and Podman containers and Compose projects.

A Clojure/ClojureScript library that automatically generates project schedules from task descriptions with constraints like resources, duration, and dependencies.

Sento is an actor framework for Common Lisp featuring actors, agents, FSMs, and an event stream for building reactive, concurrent systems.

A Vue 3 library providing TypeScript decorators for writing Vue components as ES classes.

An open-source platform for declarative deployment of containerized web apps, on a single node or Kubernetes, with built-in auth and RBAC.

A framework for building reactive, real-time frontend UI components in Amber applications using pure Crystal.

A macOS menu bar app that displays your calendar meetings and provides quick access to join or create meetings.

An open-source, real-time infrastructure monitoring platform with per-second metrics, ML-powered anomaly detection, and zero-configuration deployment.

A macOS app that gathers all windows of a selected application to your current screen with per-app window control and workspace management.

Static and dynamic D bindings to the Lua C API, compatible with BetterC, @nogc, and nothrow.

Rails integration for the Rodauth authentication framework, providing a robust, feature-rich alternative to Devise.

A durable background task queue and workflow orchestration platform built on Postgres with observability and flow control.

An all-language AI-powered code completion backend that provides intelligent autocompletions across multiple editors.

A curated list of awesome Swift Macros and learning resources for compile-time code generation in Swift.

Lightweight DataFrame validation decorators for pandas, Polars, Modin, and PyArrow with no custom types required.

A Ruby gem for interacting with REST APIs using an ActiveRecord-like interface.

A modern Java platform providing high-performance asynchronous I/O, HTTP server/client, dependency injection, and cloud components with minimal dependencies.

A Neovim plugin that enhances .NET development with automatic LSP setup, debugging, and code analysis features.

A continuous file synchronization program that securely syncs files between multiple computers without central servers.

A native macOS menu bar app for lightweight, efficient Google Drive syncing with multiple account support.

A Common Lisp implementation of the Erlang distribution protocol for interoperability between Lisp and Erlang nodes.

A high-performance, functional tabular data processing library for Clojure, similar to Python's Pandas or R's data.table.

Microsoft's production-ready distribution of OpenJDK with long-term support and security updates.

A process manager, supercharger, and load balancer for modern PHP applications that boosts performance by keeping workers in memory.