Best Self-hosted Communication & Collaboration tools in 2026
168 self-hosted open source alternatives in this category
168 services found
Prosody IM
Lightweight and extensible XMPP (Jabber) communication server
Prosody IM is a modern, resource-efficient XMPP (Jabber) server written in Lua, designed to be easy to configure and extend for private messaging and federation.
Stackspin
Open source collaboration suite with SSO and admin dashboard
Stackspin is an open source platform that bundles common team collaboration apps with single sign-on, centralized user management, backups, and monitoring for admins.
Zimbra Collaboration
Enterprise email, calendar, contacts, and collaboration suite
Self-hosted enterprise collaboration suite providing email, webmail, calendaring, contacts, and administration for organizations.
Citadel
Groupware server with email, calendaring, contacts, and web access
Citadel is an open source groupware and messaging server providing email, calendars, contacts, and a web interface with room-based collaboration.
HiveDAV
Curlable free/busy scheduler with CalDAV integration
A lightweight, curl-first free/busy scheduler that syncs availability from a CalDAV calendar and can send iCal booking invites via SMTP.
Conduit
Lightweight Matrix homeserver written in Rust
A single-binary, low-resource Matrix homeserver in Rust; simple setup, RocksDB (default) or SQLite backends, built with axum and Ruma.
Courier Mail Server (Courier MTA)
Integrated mail server suite with SMTP, IMAP, POP3 and webmail
Courier is an integrated mail server suite providing ESMTP (MTA), IMAP, POP3, webmail, and mailing lists with optional LDAP/MySQL/PostgreSQL-backed virtual accounts.
FreePBX
Web-based open-source GUI for managing Asterisk-based IP PBX systems
Modular, PHP/JavaScript web GUI that configures and manages Asterisk PBX features, endpoints, and call routing for businesses and service providers.
OpenTalk
Open-source, GDPR-compliant video conferencing platform
OpenTalk is an open-source video conferencing platform offering GDPR-compliant SaaS and self-hosted deployments with features like recording, whiteboards, breakout rooms,...
Continuwuity
Community-maintained Matrix homeserver in Rust
Continuwuity is a fast, lightweight Matrix homeserver written in Rust, focused on stability, performance, and improved Matrix specification compliance for federation.
b1gMail
Web-based email and collaboration suite for running hosted email services
Open-source webmail and groupware offering email, contacts, calendar, cloud drive, tasks, notes and an admin control panel for multi-tenant email services.
Jami
Distributed, open source communication platform for calls and messaging
Jami is a distributed communication platform for private messaging, audio/video calls, and conferencing, designed to work without central servers and with end-to-end encr...
OpenSMTPD
Secure, lightweight SMTP server implementation compliant with RFC 5321
OpenSMTPD is an open-source, minimal SMTP daemon from the OpenBSD project providing an RFC-compliant MTA with privilege separation, table backends, filters and TLS suppor...
Yeti-Switch
Carrier-grade Class 4/5 VoIP softswitch and SBC
Carrier-grade VoIP softswitch/SBC for routing, billing, and managing SIP traffic, with LCR, fraud control, and high-availability deployment options.
üWave
Collaborative music listening with real-time DJ queues
Self-hosted collaborative music room app with DJ queues, real-time chat, and YouTube/SoundCloud-style playback for shared listening sessions.
DAViCal
CalDAV server for shared calendars and scheduling
DAViCal is an open source CalDAV/WebDAV calendar server using PostgreSQL, enabling shared calendars, access delegation, and meeting scheduling across many clients.
E-MailRelay
Lightweight SMTP store-and-forward MTA with optional POP3 access
E-MailRelay is a lightweight SMTP relay/store-and-forward mail server with optional POP3 access to spooled messages, designed for simple, scriptable mail handling.
Postfix
Secure and efficient SMTP mail transfer agent (MTA)
Postfix is a fast, secure, and easy-to-administer SMTP server for sending and routing email on Unix-like systems, commonly used as an MTA or mail relay.
