Best Self-hosted Communication & Collaboration tools in 2026

Nextcloud Mail is a webmail app that connects to IMAP/SMTP accounts, offering a unified inbox and deep integration with other Nextcloud apps like Contacts and Calendar.

Alternative to:

Microsoft Outlook+11

Open-source task scheduler and calendar app that auto-plans tasks, syncs with external calendars, and provides a modern UI for managing time blocks and workflows.

Alternative to:

Google Calendar+13

Open-source self-hosted real-time location sharing backend with in-memory storage, temporary share links, a Docker image and companion mobile clients.

Alternative to:

Glympse+2

OpenTrashmail is a standalone disposable email (“trashmail”) service with its own SMTP server, offering a web UI plus JSON API, RSS feeds, and webhooks for received mail.

Alternative to:

Mailinator+3

Modern, cross-platform IRC client with a detachable core for persistent connections, multi-client access, and searchable chat backlogs.

Alternative to:

IRCCloud+3

DavMail is a Java gateway that lets standard clients use IMAP/POP/SMTP, CalDAV, CardDAV, and LDAP with Microsoft Exchange and Microsoft 365 via OWA/EWS.

Alternative to:

Proton Mail Bridge

Self-hosted disposable email server for creating temporary addresses to reduce spam and protect privacy, with an optional TLS setup and a web UI.

Alternative to:

Mailinator+3

Davis is a sabre/dav-based CalDAV/CardDAV/WebDAV server with a modern Symfony 7 admin dashboard for managing users, calendars, sharing, and address books.

Alternative to:

Google Calendar+6

Apache OpenMeetings is a web conferencing and collaboration platform with video meetings, chat, whiteboards, screen sharing, recording, file sharing, and user/room manage...

Alternative to:

Zoom+11

Nextcloud Tasks provides a web-based to-do list with priorities, due dates, subtasks, and CalDAV synchronization with mobile and desktop task clients.

Alternative to:

Todoist+8

Cyrus IMAP is a secure, scalable mail server providing IMAP/JMAP email plus CalDAV/CardDAV contacts and calendars, with ACLs, quotas, search, and replication.

Alternative to:

Microsoft Exchange Online+18

Self-hosted, privacy-respecting pictionary game (skribbl.io alternative) with real-time drawing, guessing, and multiplayer lobbies—no accounts or ads required.

Lightweight CalDAV/CardDAV server implemented in Python that stores calendars and contacts in a Git-backed hierarchy with history and sync support.

Alternative to:

Google Calendar+4

ngIRCd is a free, portable and lightweight IRC server for small/private networks, supporting IPv6, TLS, server linking, and optional PAM authentication.

Alternative to:

IRCCloud+3

Self-hosted Next.js React CalDAV client for managing VTODO tasks and VEVENT calendars with multi-account, list/Gantt/calendar views and filters.

Alternative to:

Google Calendar+10

Lightweight, customizable Discord music bot in Python. Supports YouTube, SoundCloud, Spotify, Twitch, Lavalink playback, playlists, lyrics, slash commands and Docker.

Alternative to:

FredBoat+2

Open-source web application for complex organization hierarchies: members, events, courses, mailings and payments. Plugin-based, Rails-backed, community-driven.

Alternative to:

WildApricot+12

AGPL-3.0 open-source email API for developers that can be self-hosted; supports SMTP sending, webhooks, DNS automation, observability, multi-tenancy, and project isolatio...

Alternative to:

Amazon Simple Email Service (Amazon SES)+11

Open-source, self-hosted web conferencing platform built on LiveKit and Go, offering scalable WebRTC meetings, recordings, broadcasting, collaboration tools, and AI meeti...

Alternative to:

Zoom+16

Self-hosted collaborative office suite for Nextcloud providing real-time editing, high-fidelity rendering and support for DOCX, XLSX, PPTX and ODF formats.

Alternative to:

Collabora Online+11

Self-hosted, open-source XMPP-based messaging server providing end-to-end encryption, multi-device sync, federation, secure backups, and integrated WebRTC audio/video cal...

Alternative to:

WhatsApp+17

Lightweight web application for synchronized video playback with chat, leader-controlled playback, subtitle/audio track support and Docker deployment.

Alternative to:

Watch2Gether+3

Scalable, modular XMPP/Jabber server written in Java supporting TCP, BOSH, WebSockets, federation, components, HTTP API and push notifications.

Alternative to:

Skype+12

Decentralized, browser-first chat focused on privacy and peer-to-peer interactions. Supports end-to-end encryption, WebRTC file sharing, voice/video calls, mixed-reality...

Alternative to:

Slack+10

Open-source mailing list manager for automating subscriptions, moderation, archives and message distribution with web, CLI and SOAP interfaces for large lists.

Alternative to:

Groups.io

Open-source, browser-based groupware providing calendar, email, file manager, CRM, projects, Collabora Online integration and SSO support.

Alternative to:

Microsoft Exchange Online+19

Self-hostable room display app for tablets that shows real-time room availability, integrates with Microsoft 365, Google Workspace and CalDAV, and supports on-device book...

Alternative to:

Condeco by Eptura+5

Tracim is an open-source collaboration suite offering threaded conversations, file sharing with versioning, collaborative pages, tasks and workspace organization.

Alternative to:

Microsoft SharePoint+19

Scalable email archiving solution with tamper-evident retention, full-text search, legal hold, deduplication and access controls for compliance.

Alternative to:

MailStore Server+1

A small, C-based Mail Transfer Agent for local submission and outbound relay with TLS/SMTP authentication, aimed at home and small office use.

Alternative to:

Postfix+11