Open-source Chatwork alternatives

Rocket.Chat is a communications platform written in TypeScript for teams and organizations that care about data protection. It supports real-time conversations between colleagues, with partner companies, and with customers or citizens, and its topics place it in the same space as Slack, with WebRTC for calls and meetings.

The product emphasizes control over where and how it runs. Deployment options include self-hosted servers, a managed cloud and fully air-gapped environments, with a scalable architecture and performance monitoring for workspace administration. Security and sovereignty features, including identity management, are a core part of the pitch, and the platform is built to be highly customizable, so organizations can adapt it to their own workflows and integrations.

The repository's license is listed as 'Other' on GitHub, although the topics reference an MIT-licensed community core, so confirm which components fall under which terms before relying on it commercially. It suits government bodies, enterprises and regulated industries that want a Slack-style tool they can host themselves.

Mattermost is an open-core collaboration platform you host yourself, covering team chat, workflow automation, voice calls, screen sharing and AI integrations. This repository is the primary source for core development of the platform. The server is built with Go and React, ships as one Linux binary and depends on PostgreSQL. GitHub lists the license as 'Other'.

Each month, on the 16th, a newly compiled release is published under the MIT license. You can deploy Mattermost on-premises or try it in the cloud. The project highlights use cases such as DevSecOps, incident resolution and IT service desk, and it offers native clients for Android, iOS, Windows, macOS and Linux in addition to the web interface.

Installation options include Docker, Ubuntu, a tar archive, Kubernetes, Helm and an Omnibus package. Developers can build integrations through APIs, webhooks, slash commands, Apps and plugins, and the repository links product and developer documentation, security bulletins and contribution guides. It suits engineering, security and operations teams that want controlled, self-managed team messaging.

Zulip is an open-source team chat application whose defining feature is topic-based threading within channels. The idea is to blend the strengths of email and chat, so that remote and distributed teams can follow several conversations at once and catch up later without losing context. Its topics tag it as a Slack alternative.

The project is developed by a distributed community, with more than a thousand contributors and a steady flow of commits each month, and it says it has put effort into readable, tested code and extensive contributor documentation. The server is a Python web application, and there are web, desktop, built on Electron, and mobile clients, built with React Native. Zulip is used by companies and open-source projects alike, and the README says it is designed for both live and asynchronous communication.

Zulip is licensed under Apache-2.0. You can run the server on your own infrastructure, which gives full control over data, or use the hosted service operated by the project's company. It suits teams that find flat channel-based chat chaotic and want a more structured way to keep discussions organized.

Element Web is a client for Matrix, the open protocol for decentralized messaging. It is the web and desktop application formerly known as Vector and Riot, and it lets people join rooms, chat in teams and communities, and collaborate across Matrix servers rather than inside a single vendor's network.

The client is built with TypeScript on top of the Matrix JS SDK. The README defines support tiers for browsers, covering recent versions of Chrome, Firefox, Edge and Safari on desktop, best-effort handling for ESR and extended-stable releases, and community support for mobile web. For phones and tablets the maintainers recommend the native Element X apps for Android and iOS.

It is released under the AGPL-3.0 license and is typically served from your own web host or used through the hosted app from the vendor, Element. Related products such as Element Call and the Enterprise Server Suite are mentioned as part of the wider Element offering. Changes are tracked on GitHub with regular release cycles.

Campfire is a web-based group chat application that Basecamp offers as software you run yourself, with no subscription. It covers the features people expect from team chat, including multiple rooms with access controls, direct messages, @mentions and search.

Files can be attached to messages and previewed, notifications are delivered via Web Push, and an API supports bot integrations. The Docker image bundles the web app, background jobs, caching, file serving and SSL, so a single machine is enough for a complete deployment. A pre-built image is published on the GitHub container registry.

The simplest way to deploy is ONCE, a tool that walks through setup and keeps the instance up to date automatically; you can also run the Docker image directly by following the self-hosting guide. On first launch a wizard creates the admin account, whose email address appears on the sign-in page. Campfire is written in Ruby, licensed under MIT, and open to modification.

Macro is an all-in-one workspace for teams that brings messaging, mail, documents, tasks, AI agents, calls and customer records into a single quick interface. Everything in the workspace can be linked with @ mentions and searched, so people and agents do not have to hop between separate tools to find context.

The project grew from its founders' wish for a single operating system for their startup, after using Slack, Linear, Notion, HubSpot and Superhuman, which do not work together as one system. A shared team-level memory ties the pieces together. Repository topics reference Slack, Notion and Linear as comparison points, plus MCP and agent support. The code base is written in Rust and TypeScript.

Macro is licensed under AGPL-3.0 and offers a hosted sign-up, with documentation, a demo booking and a feature request channel linked in the README. It suits startups and small teams that want to replace a stack of separate collaboration tools.

Chatto is an open-source chat application for teams and communities that is meant to be free and easy to self-host. The repository contains the chat server, a command-line tool, and a bundled web front end, and the project describes itself as fully featured. It is released under the AGPL-3.0 license.

The topics describe a privacy-first design that is GDPR-compliant, and the application includes voice calls, video calls, and screen sharing in addition to text chat. The repository also hosts related components, including Runling, an independent workflow and agent orchestrator published on npm, and Authling, an identity provider that is expected to move to its own repository.

The README says cloud hosting will be available soon, so self-hosting is the supported route today, with a documentation site and releases for installation. The authors note that Chatto is built with the help of coding agents. It is a young project created in 2026 and suits teams that want an alternative to hosted workplace chat tools.

Colanode is an all-in-one collaboration platform built around data privacy and control. It combines real-time chat, rich-text pages for documents, wikis and notes, customizable databases and file management in one workspace, positioned as an open-source alternative to Slack and Notion.

It has a client app, available on the web and as an Electron desktop app, and a self-hosted server. One app can connect to several servers, each holding one or more workspaces for different teams or projects. Databases support custom fields and table, kanban and calendar views. The local-first design writes every change to a local SQLite database first and syncs it in the background, so reads are immediate and people can keep working when offline.

The topics reference CRDTs and Yjs for real-time collaboration. Colanode is written in TypeScript and licensed under Apache-2.0, and because you run the server yourself you decide where the data is stored. It suits individuals, small projects and larger teams that want to avoid depending on a hosted vendor.

Twake, published by Linagora, was an open-source digital workplace combining team chat, file storage, a shared calendar, task management, video calls and real-time document collaboration. It was designed to improve organizational productivity, with kanban boards for tasks and a drive for files. This repository is the legacy codebase and is explicitly marked deprecated.

The README states that the repository is no longer actively maintained and directs users to the newer Twake-workplace repository for current features and support. The archived instructions describe running a local instance with Docker Compose, which serves on localhost, redirects to HTTPS and uses a self-signed certificate by default unless you disable SSL certificates in the compose file. The team also offered a hosted SaaS demo, plus documentation, a community forum and Weblate-based translations.

The code is written in TypeScript and licensed under AGPL-3.0. Anyone evaluating the product today should look at the successor project rather than adopt this repository for new deployments. It remains useful mainly for existing installations and as a reference for how the platform was built.

Teamlinker is a team collaboration platform that brings several tools into one place so companies do not need separate apps for project progress, colleague communication and client meetings. It is built on TeamOS, a web operating system in which users can run tasks in parallel in windows, similar to a desktop operating system.

It has six functional modules: project management, wiki, calendar, meetings, chat and a network disk. The web OS offers desktop management, multiple windows, multitasking, file drag and drop, upload and download. Meetings use WebRTC for multi-person video and voice, member invitations, screen sharing, virtual backgrounds, video blur, administrator controls and in-meeting chat. A custom block editor powers the wiki.

The stack is TypeScript throughout, with Node.js on the back end and Vue 3 on the front end, and mediasoup is listed among its topics. Related open-source components include TLCalendar, TLEditor, TLMeetingClient and TLMeetingServer. Teamlinker is licensed under GPL-3.0 and has documentation in English and Chinese.