Top Open Source Projects using C#

A curated collection of the 20 best open source software using C#. Find the most popular and trending open source projects to learn from, contribute to, or use in your own projects.

Uptime Kuma

Self-hosted monitoring tool that checks whether your sites, servers and containers are up and tells you the moment they are not.

Alternative to:

UptimeRobot

Self-hosted uptime monitoring with a clean dashboard

Stars
91,061
Forks
8,359
Last commit
5 days ago

Orca

Desktop orchestrator that runs several terminal coding agents side by side, each in its own git worktree, tracked in one window.

Alternative to:

Cursor

Run multiple AI coding agents in parallel, side by side

CopilotKit

SDK for developers building agent-native apps, adding chat, generative UI, shared state and human-in-the-loop across web, mobile and chat platforms.

Alternative to:

Voiceflow

Build AI copilots for your product in hours, not months

Stars

Continue

Coding agent for VS Code, JetBrains and the terminal, now shipped as a final version and no longer under active development.

Alternative to:

Cursor

Open-source coding agent for your IDE and terminal

Stars
35,812

ShareX

Windows screen capture, recording and file sharing tool that chains annotation, upload and link copying into one hotkey workflow.

Alternative to:

Bandicam

Powerful screen capture and file sharing tool for Windows

Stars
39,472

Cap

Screen recorder with local editing, instant share links and storage you control, for teams sending async video instead of meetings.

Alternative to:

Loom

Open source screen recorder with editing and instant sharing

Stars
21,864

Bitwarden

Backend server behind the Bitwarden password manager, for teams and individuals who want to host their own vault.

Alternative to:

1Password

Secure password management for individuals and businesses

Stars
20,087

Scalar

Toolkit that renders OpenAPI documents as an interactive API reference and pairs it with an offline-first API client.

Alternative to:

Postman

Open-source API documentation and testing platform

Stars
16,069

MonoGame

A C# framework for building games across desktop, mobile and console, and the open reimplementation of Microsoft's discontinued XNA.

Alternative to:

Unity

Free, open-source framework for cross-platform game development

Stars
14,399

Fumadocs

A documentation framework for React frameworks and Astro that supplies content, navigation, search and API reference as composable pieces.

Alternative to:

GitBook

Build beautiful documentation sites with Next.js

Stars
13,082

Highlight

Fullstack monitoring for web teams, pairing session replay with error tracking, logs and traces behind a few lines of setup.

Alternative to:

Datadog

Real-time observability for modern web applications

Stars
9,372

s&box

A game engine on Valve's Source 2 and .NET, with an editor for developers who want to build and ship games.

Alternative to:

Unity

Build and play games inside a game engine that runs live

OneUptime

One platform for uptime monitoring, on-call, status pages, incidents, logs, traces and metrics, replacing a shelf of separate SaaS tools.

Alternative to:

Datadog

Comprehensive monitoring and incident management platform

Stars
7,563

Rivet

A library for stateful backends where each agent, session, document or tenant runs as a long-lived actor with in-memory state.

Alternative to:

Azure Durable Functions

Build stateful backends with in-memory actors

Stars

Amical

A local-first dictation app that transcribes speech with Whisper on your own machine and formats the result for whichever app you are using.

Alternative to:

Aqua Voice

Type 10x faster with AI-powered voice dictation

Stars
1,523

Aptabase

A privacy-first analytics service for mobile, desktop, and web apps that measures sessions without unique identifiers, across a dozen SDKs.

Alternative to:

Google Analytics

Privacy-first analytics for mobile and desktop apps

Stars

Hook0

A webhooks server and dashboard your SaaS puts in front of customers, handling their subscriptions, delivery retries and event history.

Alternative to:

Hookdeck

Open-source webhooks for seamless integrations

Stars
1,484

Valour

Community platform built on .NET and Blazor where each server is a planet with chats, wikis, voice, roles and an economy.

Alternative to:

Discord

Community-driven platform built for transparency

Stars
395

Prismical

Desktop meeting notes with transcription that runs on your own machine, for people who want a record without sending audio away.

Alternative to:

Granola

Transcribe meetings and voice notes with local AI, no bots required

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Top Open Source Projects using C#

A curated collection of the 20 best open source software using C#. Find the most popular and trending open source projects to learn from, contribute to, or use in your own projects.

Uptime Kuma

Orca

CopilotKit

Continue

ShareX

Cap

Bitwarden

Scalar

MonoGame

Fumadocs

Highlight

s&box

OneUptime

Rivet

Amical

Aptabase

Hook0

Valour

Prismical

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Uptime Kuma

Orca

CopilotKit

Continue

ShareX

Cap

Bitwarden

Scalar

MonoGame

Fumadocs

Highlight

s&box

OneUptime

Rivet

Amical

Aptabase

Hook0

Valour

Prismical

Jellyfin