1. Introduction §

As a human being I have to communicate with other people and now we have many ways to speak to each other, so many that it's hard to speak to other people. This is a simple list of communication protocol and why you would use them. This is an opinionated text.

2. Protocols §

We rely on protocols to speak to each other, the natural way would be language with spoken words using vocal chords, we could imagine other way like emitting sound in Morse. With computers we need to define how to send a message from A to B and there are many many possibilities for such a simple task.

• 1. The protocol could be open source, meaning anyone can create a client or a server for this protocol.
• 2. The protocol can be centralized, federated or peer to peer. In a centralized situation, there is only one service provider and people must be on the same server to communicate. In a federated or peer-to-peer architecture, people can join the communication network with their own infrastructure, without relying on a service provider (federated and peer to peer are different in implementation but their end result is very close)
• 3. The protocol can provide many features in addition to contact someone.

2.1. IRC §

The simplest communication protocol and an old one. It's open source and you can easily host your own server. It works very well and doesn't require a lot of resources (bandwidth, CPU, memory) to run, although it is quite limited in features.

• you need to stay connected to know what happen
• you can't stay connected if you don't keep a session opened 24/7
• multi device (computer / phone for instance) is not possible without an extra setup (bouncer or tmux session)

I like to use it to communicate with many people on some topic, I find they are a good equivalent of forums. IRC has a strong culture and limitations but I love it.

2.2. XMPP (ex Jabber) §

Behind this acronym stands a long lived protocol that supports many features and has proven to work, unfortunately the XMPP clients never really shined by their user interface. Recently the protocol is seeing a good adoption rate, clients are getting better, servers are easy to deploy and doesn't draw much resources (i/o, CPU, memory).

XMPP uses a federation model, anyone can host their server and communicate with people from other servers. You can share files, create rooms, do private messages. Audio and video is supported based on the client. It's also able to bridge to IRC or some other protocol using the correct software. Multiples options for end-to-end encryption are available but the most recent named OMEMO is definitely the best choice.

The free/open source Android client « Conversations » is really good, on a computer you can use Gajim or Dino with a nice graphical interface, and finally profanity or poezio for a console client.

XMPP on Wikipedia

2.3. Matrix §

Matrix is a recent protocol in the list although it saw an incredible adoption rate and since the recent Freenode drama many projects switched to their own Matrix room. It's fully open source in client or servers and is federated so anyone can be independent with their own server.

As it's young, Matrix has only one client that proposes all the features which is Element, a very resource hungry web program (web page or run "natively using Electron, a program to turn website in desktop application) and a python server named Synapse that requires a lot of CPU to work correctly.

In regards to features, Matrix proposes end to end encryption, rooms, direct chat, encryption done well, file sharing, audio/video etc...

While it's a good alternative to XMPP, I prefer XMPP because of the poor choice of clients and servers in Matrix at the moment. Hopefully it may get better in the future.

Matrix protocol on Wikipedia

2.4. Email §

This way is well known, most people have an email address and it may have been your first touch with the Internet. Email works well, it's federated and anyone can host an email server although it's not an easy task.

Mails are not instant but with performant servers it can only takes a few seconds for an email to be sent and delivered. They can support end to end encryption using GPG which is not always easy to use. You have a huge choice for email clients and most of them allow incredible settings choice.

I really like emails, it's a very practical way to communicate ideas or thoughts to someone.

2.4.1. Delta Chat §

I found a nice program named Delta Chat that is built on top of emails to communicate "instantly" with your friends who also use Delta Chat, messages are automatically encrypted.

The client user interface looks like an instant messaging program but will uses emails to transport the messages. While the program is open source and Free, it requires electron for desktop and I didn't find a way to participate to an encrypted thread using an email client (even using the according GPG key). I really found that software practical because your recipients doesn't need to create a new account, it will reuse an existing email address. You can also use it without encryption to write to someone who will reply using their own mail client but you use delta chat.

Delta Chat website

2.5. Telegram §

Open source client but proprietary server, I don't recommend anyone to use such a system that lock you to their server. You would have to rely on a company and you empower them by using their service.

Telegram on Wikipedia

2.6. Signal §

Open source client / server but the main server where everybody is doesn't allow federation. So far, hosting your own server doesn't seem a possible and viable solution. I don't recommend using it because you rely on a company offering a service.

Signal on Wikipedia

2.7. WhatsApp §

Proprietary software and service, please don't use it.

3. Conclusion §

I daily use IRC, Emails and XMPP to communicate with friends, family, crew from open source projects or meet new people sharing my interests. My main requirement for private messages is end to end encryption and being independent so I absolutely require federated protocol.