Open-source alternatives to Android

A chat server with OAuth2 authentication, persistent and searchable history, video and audio, markdown formatting, private and public rooms, stars, votes, embedded games, and many other features

Apprise is a notification library and command-line utility that provides a unified interface for sending alerts to a wide range of messaging, email, and push services. It abstracts the complexities of diverse third-party communication APIs, allowing users to dispatch notifications through a single, standardized method. The project utilizes a connection-string-based routing system to map notification requests to specific service drivers. It features a modular plugin architecture that supports the integration of new messaging platforms and custom notification hooks. Users can organize service e

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

Chatwoot is a self-hosted, omnichannel customer support platform designed to aggregate messages from diverse social and digital channels into a single, collaborative team inbox. It provides organizations with full data ownership and control over their support infrastructure, ensuring strict logical separation of customer data through multi-tenant architecture. By centralizing communication, the platform enables teams to manage, route, and resolve inquiries within a unified workspace that maintains complete interaction history for every contact. The platform distinguishes itself through an eve

Ephemeral, encrypted, in-browser chat rooms

End-to-end encrypted instant web chat

Element Web is a web-based communication client used for real-time messaging and collaboration via the decentralized Matrix protocol. It functions as an end-to-end encrypted messenger, a VoIP client for voice and video conferencing, and an interface for interacting with integrated bots and external bridges. The project distinguishes itself through a modular architecture that supports runtime module loading and external script imports to extend core capabilities. It provides extensive white-labeling options, allowing for the customization of application branding, visual themes, and the use of

Eyevinn Open Intercom is a low latency, web based, open source, high quality, voice-over-ip intercom solution. It is designed to be used in broadcast and media production environments, where low latency and high quality audio are critical. The solution is built on top of WebRTC technology and…

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

Freenet REference Daemon

Secure peer-to-peer chat that is serverless, decentralized, and ephemeral

Yopass is a secure secret sharing platform used to share encrypted text and files via one-time expiring links. It utilizes client-side encryption to ensure that sensitive data is encrypted in the browser before transmission, preventing the server from seeing plain text. The platform differentiates itself through an integrated security auditing system that generates structured logs and triggers cryptographically signed webhooks when secrets are created, viewed, or expired. It also features an access control system based on OpenID Connect, allowing administrators to restrict secret creation and

Whitebophir is a collaborative whiteboarding application designed for real-time visual collaboration. It enables multiple users to brainstorm and create content together on a shared virtual canvas using freehand sketching, geometric shapes, and text labels. The platform focuses on private workspace management, allowing the creation of restricted boards via unique URLs and token-based access control to manage editing permissions. It integrates real-time state synchronization for drawing updates and a built-in chat system for text communication between collaborators. The workspace includes too

Rallly is a group scheduling tool and collaborative event planner designed to coordinate meeting dates and collect participant availability. It functions as a multi-tenant meeting coordinator that allows users to propose date options via polls, visualize overlapping free time in a grid, and finalize meeting arrangements across different time zones. The project is built as a self-hosted scheduling application that can be deployed on private infrastructure using a containerized stack. This deployment model enables full data ownership and includes capabilities for corporate identity branding, al

One-Time-Secret sharing platform with a symmetric 256bit AES encryption in the browser

A githubbed version of DIY intercom system based on Murmur voice chat server and headless Mumble client running on Raspberry Pi 3 based beltpacks. It has been originally developed by Niclas Hallgren of Institutionen för Kultur och Media, Arcada UAS, Finland and funded by the university fund for…

Dendrite is a second-generation Matrix homeserver written in Go, designed to handle room management, federation, and client API traffic for real-time communication. It implements the Matrix protocol for federated messaging, presence, and encrypted communication, and can be deployed as a self-hosted platform that manages user accounts, rooms, media, and end-to-end encryption. The server uses a modular architecture where independent components communicate through an internal message bus, supporting federation with remote homeservers, full-text search indexing of message content, presence broadc

Synapse is a decentralized communication server implementation that enables real-time messaging and data exchange across the global Matrix federation. It functions as a homeserver, allowing operators to host their own nodes while maintaining control over personal data and user identity within a distributed network. The server utilizes a federated messaging protocol to exchange messages and user data with independent servers, ensuring consistent state across the network. To support high-traffic environments, it employs a distributed service architecture that offloads tasks to independent backg

Mattermost is a self-hosted, enterprise-grade communication platform designed for organizations that require strict control over their internal data and messaging infrastructure. It functions as a centralized hub for real-time team interaction, offering persistent messaging, voice and video conferencing, and integrated project management tools within a single, private workspace. The platform is built to support high-security environments, including air-gapped deployments where public internet access is restricted or unavailable. The platform distinguishes itself through a focus on regulatory

Mibew Messenger - open-source live support application

Next generation noIM application in your own workspace, not only another Slack/Discord/Rocket.chat

Mumble is a low-latency voice over IP system designed for real-time communication. It provides a self-hosted, encrypted voice server that secures data transmission using public-private key authentication and digital certificates. The platform distinguishes itself through a request-response protocol for remote configuration and integration with external automation scripts. It also features a graphical overlay that renders active speaker information and chat status on top of other running applications, as well as positional audio to simulate the 3D spatial location of speakers in a virtual envi

Talk is a real-time users messaging and chatting system for Laravel.

Example bluetooth chat app using Bluetooth LE library to communicate between android devices