The area of messaging — instant chat as well as email — is today marked by massive centralization of power in the hands of a few operators. Even email, though designed as a federated system, often offers little privacy in practice: protection is not always on by default, nor easy to turn on. Metadata about who talks to whom, when, and often from where, usually remains exposed on the tools most people use every day.

This dossier presents NGI-funded messenger projects alongside widely used FLOSS alternatives — from federated XMPP and Matrix clients to peer-to-peer, mesh, and off-grid radio messengers.

The projects in this dossier each target specific harms of centralized messaging. None replaces every proprietary app overnight, but together they show how inspectable messenger code, federation, peer-to-peer sync, and end-to-end encryption can reduce dependence on a single operator:

	Dino offers a polished desktop client for XMPP instant messaging with end-to-end encryption options. Federation lets communities choose their own server or run one locally, rather than routing every contact through one company's identity graph — though trust and metadata still depend on the homeserver operator you pick.
	Briar Desktop synchronises encrypted messages directly between devices without a central server. When the internet is unavailable it can sync over Bluetooth, Wi-Fi, or removable media; when online it can use the Tor network — reducing exposure to server-side metadata collection and outages that silence centralized apps.
	Qaul is a delay-tolerant mesh messenger for off-the-grid and emergency use. Configurable, verifiable P2P channels support open discussions, trusted information feeds, and distributed spam protection without requiring always-on cloud relays.
	Conversations is a mature Android messenger for federated XMPP with end-to-end encrypted text, media, and voice messages — plus standards-based audio and video calls. Users can pick or run their own server instead of locking contacts into one company's app.
	NeoChat is a cross-platform Matrix messenger from KDE. NGI funding brought end-to-end encryption to the client via libQuotient, so private and professional chats on open federation need not stay plaintext or tied to a single vendor's closed app.
	Monal is an XMPP messenger for iOS and macOS — the Apple-platform counterpart to Conversations. NGI funding added OMEMO encryption and audio/video calls, so people on iPhone and Mac can join the same federated network without a closed vendor app.
	Delta Chat turns an ordinary email address into an instant messenger. Chats are end-to-end encrypted with Autocrypt / OpenPGP and can run on regular mail or dedicated chatmail servers. NGI-funded work includes a lighter desktop client (Delta Tauri) and WebXDC apps that travel inside the chat.
	PulzeLab C1 (LoraMessaging) is a handheld LoRa mesh messenger: small packets over open UHF ISM bands, no cellular or internet operator in the path. The grant funds an affordable, durable device so people can join a mesh without a phone contract — everyday use and crisis comms on low-power radio rather than a central chat server.
	MAGNET Communicator is an open-hardware short-range (up to 3 km) voice radio using MANET — no base station and no licence. Schematics, firmware, 3D-printable enclosure, and assembly docs use permit-free parts so the device stays repairable when cellular infrastructure is gone.
	TETRA BlueStation is a FLOSS TETRA base-station stack. A previous grant shipped a proof of concept; this one aims at a usable station on about €200 of hardware so surplus handheld TETRA radios can carry voice, text, and IP without vendor lock-in — one cell or a network of stations linked over the internet.

Browse the NGI-funded projects in this dossier below.

Beyond NGI-funded work, several widely used FLOSS tools shape everyday messaging — from mobile chat apps to Matrix clients and self-hostable team platforms. They are a common step away from purely proprietary services, but each still comes with structural limits.

Signal ships open clients and strong end-to-end encryption. As of 2026, sign-up still requires a phone number, but usernames and default number privacy mean you need not share that number with contacts; discovery by number can be restricted. The service nonetheless depends on centrally operated Signal servers — availability and much metadata remain tied to that infrastructure.

Session routes messages over onion-style networks without a phone number, which improves anonymity compared with mainstream apps. Users still rely on the project's network design and release cycle rather than direct peer-to-peer delivery between contacts.

SimpleX Chat has no user identifiers — not even usernames. Contacts exchange invitation links or QR codes; messages go through relays that cannot look people up by account. Users still depend on those relays and the project's own clients rather than a classic federated address.

Jami is a GNU P2P messenger for chat, audio, and video. There is no central account server and no phone number: identity lives on the device. Connectivity still depends on DHT and TURN helpers when peers sit behind NAT, so it is not a complete substitute for a well-run federated server.

Element is the Matrix client most people actually meet first — web, desktop, and mobile, with optional end-to-end encryption. Federation can reduce single-vendor lock-in, but most accounts still live on a large public homeserver such as matrix.org, so trust and metadata shift to that operator. Element is developed by a company that also sells hosted Matrix; the clients are FLOSS, the default path is not self-hosted.

FluffyChat is a Matrix client: open federation can reduce single-vendor lock-in, but most people depend on a homeserver they do not run — often a large public instance — so trust and metadata exposure shift to that operator.

Mattermost can be self-hosted for teams, which helps organisations keep data under their own control. In practice many deployments sit behind central IT, target workplace collaboration, and do not offer end-to-end encrypted private chat by default.

These projects show what “FLOSS messaging” often means in the field: inspectable code with remaining reliance on central or hosted infrastructure — useful, but not a full substitute for decentralised, metadata-resistant designs.

Most people still chat on proprietary messengers whose clients and servers are not fully inspectable or self-hostable. They are included here as reference points — not recommendations — because their defaults illustrate the centralization and metadata exposure this dossier tries to reduce.

WhatsApp markets end-to-end encryption, but Meta still collects extensive metadata, ties accounts to phone numbers, and operates the sole authoritative server infrastructure.

Telegram is widely used for groups and channels, yet default chats are not end-to-end encrypted, server code is closed, and users depend on Telegram's centralized service for availability and account recovery.