Alternative a Slack

Element

🇬🇧

by Element

Element is a secure messenger and collaboration platform built on the Matrix open protocol, developed by Element (formerly New Vector) in London, UK. It provides end-to-end encrypted messaging, voice/video calls, and bridging to other platforms (Slack, Teams, WhatsApp). Element is used by the French government, German military (Bundeswehr), and NATO for secure communications. Organizations can self-host for complete data sovereignty, or use Element's managed hosting.

BirdyChat

🇱🇻

by BirdyChat

BirdyChat is a dedicated messaging app for professionals, enabling chats that keep work conversations separate from personal ones, while also allowing users to send and receive WhatsApp messages. It is designed for focused exchanges and collaborative work, with a commitment to end-to-end encryption.

Vroff

🇸🇪

by Vroff

Vroff is a Swedish all-in-one digital workspace that bundles video meetings, threaded chat, project management, a shared calendar, and team metrics into a single platform. Built around a rooms model — team members move between rooms to see who is available and collaborate in real time, similar to Discord but positioned for work. Developed and hosted in Sweden by the privately-owned Zápas Group (parent of SMS Teknik, TellusTalk, and InTime, a 20+ year Swedish software operator). Data is AES-encrypted at rest on Swedish cloud infrastructure; the product complies with GDPR, DORA, and NIS2. End-to-end encryption is on the roadmap but not yet shipped, and a native mobile app is planned for summer 2026. Free for up to 100 users per office.

Wire

🇨🇭

by Wire

Wire is a secure collaboration platform founded in 2012 by Janus Friis (Skype co-founder) and headquartered in Zug, Switzerland. It offers end-to-end encrypted messaging, voice/video calls, and file sharing for teams. Wire is open source, independently audited, and used by government agencies and enterprises across Europe for classified communications. It supports self-hosted deployment for organizations requiring full data sovereignty.

Stackfield

🇩🇪

by Stackfield GmbH

Stackfield is an all-in-one project management tool designed for organizations that handle sensitive data. It provides features for secure communication and collaboration, making it ideal for sectors like government, banking, and education.

Stoat

🇬🇧

by Stoat

Stoat (formerly Revolt, rebranded in October 2025) is an open-source, privacy-focused messaging platform built in the UK. It provides a familiar Discord-like experience with servers, channels, voice chat, and rich media sharing — but with full GDPR compliance and EU data hosting. Stoat is fully self-hostable, giving communities and teams complete control over their data. It features fine-grained role-based permissions, end-to-end encryption, and does not require a phone number or real name to register. Ideal for privacy-conscious communities looking for a feature-rich alternative to Discord.

MeisterTask

🇩🇪

by Meister

MeisterTask is a German-made intuitive project and task management tool built on Kanban boards. Offers seamless collaboration with time tracking, automation, and integrations. GDPR compliant with EU data hosting. Integrates well with MindMeister for mind mapping.

OpenProject

🇩🇪

by OpenProject GmbH

OpenProject is an open source project management software providing powerful classic, agile, or hybrid project management solutions in a secure environment. It enhances team productivity and allows for seamless collaboration across various project methodologies.

Teamwork

🇮🇪

by Teamwork.com

Teamwork is an Irish project management platform designed for client work and agencies. Offers comprehensive features including time tracking, resource management, and billing. GDPR compliant with EU headquarters in Cork, Ireland.

Zenkit

🇩🇪

by Axonic Informationssysteme

Zenkit is a versatile project management tool that enables teams to collaborate effectively through various methodologies, providing features like Kanban boards, Gantt charts, and resource management all in one platform.

Threema

🇨🇭

by Threema

Threema is a Swiss encrypted messenger founded in 2012 by Manuel Kasper in Pfäffikon, Switzerland. Unlike most messaging apps, Threema requires no phone number or email to register — users get a random Threema ID, enabling truly anonymous communication. All messages, calls, and files are end-to-end encrypted, and metadata is minimized by design. Threema is fully open source and has been independently audited. It's widely adopted in German-speaking countries and used by the Swiss government and military.