Open Source Rust Messaging Platforms

ZapFast is a free, open-source WhatsApp desktop client developed with Rust and egui. It provides a native messaging experience without relying on an embedded browser engine. Users can link their WhatsApp accounts through QR code scanning or phone number pairing. The application supports text messages, attachments, voice messages, stickers, reactions, polls, and message forwarding. Multiple WhatsApp accounts can be accessed within the same window. Conversations are stored in an encrypted local archive, with older messages retrieved as users scroll. Additional features include chat history exporting, keyboard shortcuts, desktop notifications, and customizable themes. Available for Windows, macOS, and Linux, ZapFast emphasizes fast startup, efficient resource usage, and local data privacy.

qq-chat-exporter is a free, open-source utility designed to extract, preserve, and back up chat histories from Tencent QQ. It supports NT QQ and allows users to export conversations with individual contacts and groups. The application can save messages in formats including HTML, JSON, TXT, and Excel. It also retrieves multimedia attachments such as images, videos, and stickers for local storage. All chat data is read and processed locally without uploading conversations to external servers. Its browser-based interface simplifies selecting and exporting conversation records. QQ Chat Exporter offers Windows installation, command-line execution, and Docker deployment options for flexible chat archiving.

Robrix is a free, open-source Matrix messaging client designed for decentralized communication across desktop and mobile devices. Built with Rust and the Makepad UI toolkit, it provides a native interface for connecting to Matrix homeservers. Users can participate in chat rooms, exchange direct messages, and browse conversation histories. The application supports formatted messages, image attachments, reactions, replies, and message editing. It includes end-to-end encrypted message decryption with device verification for secure conversations. Additional capabilities include room searching, membership management, read receipts, and offline message caching. Robrix also supports account authentication, user profiles, and Matrix Spaces. Developed through Project Robius, it targets Windows, macOS, Linux, Android, and iOS.

Aero P2P Chat is a simple chat app for Windows, Linux, and Android. Connect directly with friends using a Peer ID. Your messages are sent between chat partners instead of being routed through a central chat server. Features include direct messaging, screen sharing, and fast connections. To start, open the app, share your Peer ID with a friend, enter their Peer ID, select Connect, and begin chatting. Source code and updates: https://github.com/AeroP2PChat/AeroP2PChat License: MIT

libsignal is the foundational cryptographic library that implements the Signal Protocol and other essential primitives used across the official Signal clients and servers, enabling secure end-to-end encrypted communication. Written primarily in Rust with bindings and APIs surfaced for Java, Swift, and TypeScript, this library encapsulates critical algorithms like the Double Ratchet, prekey mechanisms, secure key storage, and zero-knowledge group primitives, along with additional utilities for media handling and device key transfer. libsignal abstracts complex cryptographic constructions into reusable components that client applications can adopt to ensure forward secrecy, authentication, and integrity without re-implementing core security logic. Although its primary use is within the Signal ecosystem, its documentation and exposed interfaces allow developers to explore modern secure messaging primitives or use pieces of the protocol in experimental applications.