Open-source alternatives to Simplex Chat

Proxychains is a SOCKS proxy chain tool and TCP traffic redirector that forces outgoing network connections from applications into a specified sequence of proxy servers. It functions as a proxy sequence orchestrator, routing TCP network traffic through multiple SOCKS or HTTP proxies to anonymize network paths and bypass firewalls. The tool includes a remote DNS resolver that performs domain name resolution through a remote proxy to prevent DNS leaks and hide queries. This ensures that network traffic from applications that are not proxy-aware is redirected through the configured intermediarie

Diaspora is a federated social networking platform that allows users to run and manage self-hosted community servers, known as pods. It operates as a distributed network where independent server nodes exchange content and users using open protocols and standardized communication schemas. The platform is distinguished by its focus on decentralized identity management and privacy-preserving communication. It includes a privacy-focused media proxy that routes external assets through a local server to protect user identity and supports cross-instance account migration, allowing users to move thei

Toxcore is a peer-to-peer networking library that implements a decentralized communication protocol for secure messaging and media calls without the use of central servers. It provides a core engine for establishing direct encrypted connections between devices using a public-key identity system where unique identifiers serve as both addresses and authentication keys. The project features a decentralized network architecture that utilizes a distributed hash table for peer discovery and Kademlia-based routing to locate participants. To maintain connectivity across restrictive network environmen

gost is a multi-protocol proxy tunnel and secure tunneling server designed to route network traffic through encrypted connections. It functions as a traffic obfuscation gateway and a transparent proxy server capable of intercepting TCP and UDP traffic at the IP level. The project also includes a virtual network interface manager for creating TUN and TAP devices to intercept operating system packets. The system distinguishes itself through a chain-based request routing model, allowing traffic to pass through an ordered sequence of proxy nodes. It provides extensive transport-layer encapsulatio

This project is a community-curated directory of open-source software designed for deployment in private server environments and home labs. It serves as a comprehensive resource for discovering independent, self-hosted alternatives to mainstream cloud services, enabling users to maintain full data ownership and control over their digital infrastructure. The directory is structured through a hierarchical taxonomy that organizes a vast collection of applications into logical categories, ranging from media management and data analytics to private communication and team productivity tools. It dis

Converse.js is an embeddable, self-hosted XMPP chat client that runs entirely in the browser. It communicates with XMPP servers using standard XML stanzas over WebSocket or BOSH transports, and provides end-to-end encryption through the OMEMO protocol with double ratchet algorithm and X3DH key exchange. The client is built on a plugin-based architecture that allows extending core functionality at runtime without modifying the client itself, and uses a DOM-based rendering approach with an event-driven message bus for internal coordination. The client manages message history through XEP-0313 Me

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

Bitchat is a decentralized messaging protocol designed for secure, private communication across both local and wide-area networks. It functions as an encrypted offline messenger that enables direct data exchange between devices without requiring centralized servers or persistent internet connectivity. By utilizing end-to-end encryption, the platform ensures that message content remains confidential and protected from unauthorized access throughout the entire transport process. The project distinguishes itself through a hybrid connectivity layer that dynamically routes messages between short-r

Tinyauth is an authentication middleware service and identity provider that verifies user identities to grant system access. It operates as a standalone server or as an authentication gateway, utilizing a reverse proxy model to intercept requests and validate credentials before traffic reaches protected backend services. The project functions as an OpenID Connect provider for single sign-on experiences and an OAuth 2.0 gateway that delegates verification to external providers such as Google and GitHub. It also acts as an LDAP authentication server, allowing for centralized user management and

Zulip is an open-source, self-hosted chat platform designed for real-time team communication. It organizes conversations into threaded streams, allowing users to maintain focus and manage complex discussions within a private, secure infrastructure. The project provides full control over data, authentication, and server management, making it a comprehensive solution for organizations requiring a dedicated messaging environment. The platform distinguishes itself through a hybrid backend architecture that combines a robust web framework for standard requests with an asynchronous event-streaming

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

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

Lets-chat is a self-hosted team communication platform and XMPP chat server designed for private messaging. It provides a containerized communication environment for small teams to exchange messages and files, featuring a programmable REST API for automating conversations and managing messages from external tools. The platform functions as an XMPP gateway and server, ensuring interoperability with other compliant messaging clients. It distinguishes itself by supporting enterprise identity management, allowing administrators to verify user identities through local accounts or external director

This is a mobile object database and NoSQL local data store that replaces relational tables with a schema-based model. It functions as a reactive data store, using live object observations and change notifications to trigger automatic user interface refreshes. The system provides built-in mobile cloud data synchronization to keep local datasets consistent with a remote server across multiple devices. It also includes security features for encrypted local storage, protecting sensitive on-disk data using at-rest encryption keys and fine-grained access control. Broad capabilities include object

This project is an Android messaging application and a client implementation of the MTProto protocol. It serves as a native mobile interface for real-time communication and file sharing on the Android operating system. The application functions as a client that connects to the Telegram MTProto protocol to facilitate the transmission of encrypted text and media messages between users. The system includes capabilities for secure mobile communication, messaging API integration, and the implementation of client-side logic for connecting to a centralized messaging backend.

BitChat Android is a decentralized peer-to-peer messenger that enables communication over Bluetooth mesh networks without requiring any internet connection or central servers. It functions as a full mesh network chat app and a privacy-focused communication tool, with every message encrypted end-to-end using per-session cryptographic keys that ensure forward secrecy. The app operates without accounts or persistent identifiers, resisting user tracking at the protocol level. To strengthen privacy and efficiency, BitChat injects cover traffic to obscure real communication patterns and includes an

Cim is a distributed instant messaging system and server-side backend designed to manage real-time communication across a cluster of servers. It provides a scalable infrastructure for routing private and group messages while tracking user connection states and session locations across distributed nodes. The project features an interception layer for AI messaging middleware, which allows artificial intelligence agents to intercept incoming communication and generate automated responses. It also includes a real-time push infrastructure to deliver notifications and messages from the server to en

FairEmail is an open-source email client for Android that supports standard IMAP and SMTP protocols. It serves as a privacy-focused communication tool that manages multiple accounts through a unified inbox and provides PGP encryption and decryption for secure messaging. The application prioritizes data privacy by blocking tracking pixels and requiring manual confirmation before loading external images. It secures sensitive information through biometric authentication and personal identification numbers to restrict unauthorized access to the device. The client includes a suite of organization

OnionShare is a privacy-focused data transfer tool and onion service host. It enables the anonymous sharing of files and the hosting of websites by creating temporary hidden services on the Tor network. The software functions as a peer-to-peer system that moves data directly between endpoints without utilizing central third-party servers. It provides capabilities for anonymous file sharing, website hosting, and encrypted peer-to-peer chat, ensuring the identities and IP addresses of participants remain hidden. Communication is secured through end-to-end encryption and Tor-based onion routing

I2P is a decentralized anonymous network layer and peer-to-peer overlay network. It functions as a darknet infrastructure that encrypts traffic and masks user identities and locations from external observers. The system acts as an anonymous proxy gateway, enabling the hosting of hidden services and websites that are unreachable via the public internet. It provides capabilities for privacy-preserving web mirroring and private secure shell tunneling to hide the physical IP addresses of both servers and clients. The network employs garlic routing, unidirectional tunneling, and a distributed has

Searx is a privacy-respecting metasearch engine and search result aggregator. It functions as a self-hosted search proxy that queries diverse web services, databases, and local indices to present a single unified list of results. The project prevents user tracking and profiling by acting as an intermediary between the client and search services. It strips identifying information from queries, removes tracker URLs and HTTP referrers from outgoing links, and can route traffic through proxies or the Tor network to mask user identity. The system supports multilingual search and result filtering

Signal-Desktop is a cross-platform messaging application that provides end-to-end encrypted communication. It implements the Signal Protocol to secure messages and voice calls, ensuring that only intended recipients can access content. The application manages asynchronous key exchange and session initialization to maintain secure communication channels between parties who are not online simultaneously. The project distinguishes itself through advanced cryptographic protections, including hybrid post-quantum security that combines classical elliptic curve cryptography with lattice-based algori

3proxy is a multi-protocol proxy server and network access control gateway. It functions as a network traffic forwarder capable of routing TCP and UDP traffic across HTTP, SOCKS, and various email and file protocols. The project provides specialized capabilities for secure traffic inspection, including the decryption and analysis of HTTPS and TLS streams through certificate spoofing and mutual authentication. It further supports client identity anonymization by routing outbound traffic through recursive upstream proxy chains. The software covers a broad range of network management functions,

Orbot is an Android network anonymization tool designed to route mobile internet traffic through the Tor network. Its primary purpose is to hide a user's identity and location from websites by masking the originating network address. The software enables users to bypass internet censorship to access blocked services and prevents trackers from identifying a mobile device. It provides a local SOCKS proxy configuration to force specific applications to send traffic through an encrypted tunnel. The application utilizes the Android VPN service to capture device traffic at the network layer and in

Haven is an Android physical security monitor that uses device sensors to detect unauthorized intrusions into a personal space. It functions as an encrypted intrusion alert system and an on-device security logger that captures images and audio when sensor thresholds are exceeded. The project incorporates a Tor-based remote monitor, allowing users to retrieve event logs and captured media from a distant location via secure onion services. It ensures privacy by routing intrusion alerts through encrypted messaging channels and saving media directly to the device filesystem rather than using clou

Open vSwitch is a software-defined network switch and high-performance data plane engine. It functions as a virtual layer 2 switch and network orchestrator, implementing the OpenFlow protocol to decouple the control plane from the data plane for programmable network forwarding. The project distinguishes itself through a userspace-kernel datapath split and the use of poll-mode drivers for kernel-bypass acceleration. It provides a network tunneling gateway to extend virtual networks across physical hosts and utilizes a transactional, schema-based configuration database with state replication fo

PrivateBin is a self-hosted, zero-knowledge text hosting service and secret sharing tool. It utilizes browser-based AES 256-bit encryption to ensure that data is encrypted on the client side before transmission, meaning the hosting server cannot read or recover the original content. The project distinguishes itself by using URL fragments to distribute decryption keys, preventing the secret key from ever being sent to the server. It supports the distribution of both encrypted text and files, which are compressed and encrypted locally prior to storage. The platform includes capabilities for an