Open-source alternatives to CPP DrawGuess

Centrifugo is a self-hosted real-time messaging server that provides infrastructure for scalable notifications, a publish-subscribe message broker, and a language-agnostic WebSocket gateway. It allows for the delivery of instant messages and data streams to concurrent users via WebSockets and Server-Sent Events. The system functions as a communication layer that separates network transport from backend business logic. It supports distributed messaging clusters using Redis for coordination of presence and message delivery across multiple server nodes. The project covers channel subscription m

Gotify is a self-hosted notification server designed to centralize the receipt and dispatch of real-time messages. It provides a RESTful API and a WebSocket gateway, allowing users to programmatically send alerts and push notifications to connected clients. By maintaining a private infrastructure, the platform ensures full control over message history, data retention, and access management. The system distinguishes itself through a modular, plugin-based architecture that allows for the extension of core functionality, including custom HTTP endpoints and webhook event processing. It supports g

Nakama is a distributed server framework designed for real-time multiplayer games and social applications. It provides an authoritative runtime environment for executing game logic, ensuring consistent state and cheat-resistant gameplay across diverse client platforms. The system acts as a centralized backend, managing persistent player identities, social graphs, and real-time communication channels to support complex multiplayer interactions. The platform distinguishes itself through an integrated suite of LiveOps tools that allow developers to manage game economies, schedule time-bound even

This project is an end-to-end encrypted communication client designed for secure messaging and identity management using public-key cryptography. It provides a cryptographic identity manager to verify authenticity across platforms and integrates a local messaging daemon to synchronize encrypted data and handle network communication. The system features a remote encrypted file system that mounts encrypted storage as local directories for direct file interaction. It also includes automated identity provisioning for registering and authenticating new devices and automation bots using cryptograph

Open-IM-Server is an instant messaging server and cross-platform messaging backend designed for real-time text and media communication. It provides a distributed chat architecture that coordinates user sessions and group communications across multiple server nodes to support millions of concurrent users. The system features a scalable message distribution model that utilizes asynchronous message pipelines and distributed queueing to maintain reliability during traffic spikes. It employs multi-level data caching across local memory and distributed stores to reduce latency and uses a document-b

This project is a cross-platform implementation of the WebRTC standard, providing a comprehensive library for building real-time audio, video, and data communication applications. It functions as a peer-to-peer networking framework and media processing engine, enabling direct, low-latency connections between devices without relying on central servers. By strictly adhering to official protocol specifications, the library ensures interoperability with browsers and other native communication software across mobile, desktop, and server environments. The engine distinguishes itself through a modul

goim

This project is a self-hosted, cross-platform instant messaging platform featuring a Go backend and a protobuf-based messaging server. It provides a unified communication suite with native clients for iOS, Android, and web, utilizing gRPC and Protocol Buffers for efficient data exchange. The system is distinguished by an extensible chatbot framework that allows for the integration of automated bots and plugins via standardized service interfaces. It supports high-availability clustering with sharded load distribution and a pluggable database backend to ensure reliability and flexible data per