Precisely. There's already the beginnings of a WhatsApp bridge for Matrix (and indeed anything that libpurple can speak) at https://github.com/matrix-org/node-purple/tree/master/appser.... It just needs tuits for people to work on and finish off. Meanwhile, the IRC & Slack bridges are live and work relatively well today (although a lot more work still to be done).

The problem is Whatsapp is actively hostile to any kind of attempts to creating 3rd party clients or APIs.

Exactly, and this is the problem with the state of messaging in 2016. The companies have built their walled gardens and are now actively defending them against "outsiders". It's to the point where I've considered buying an iDevice just to communicate with a few friends on iMessage.

Strange thing is this was always the case and just recently started to change. MSN API was a joke, you needed a desktop environment on the server to run the actual client to use SOME of the functionality. Nearly the same with Skype. Gchat removed Jabber pretty fast. Facebook chat also removed the outside functionality of their XMPP clone. Whatsapp is not even able to provide a web client, but only a weired bridge because they crippled to xmpp they are using way to much. No experience with the Apple services but i assume they are similar.

Next to that we always had open protocols, that worked perfectly, had plenty of clients and apps and nobody used them.

It is a stupid market.

Convince them to get Telegram. It works on most devices, and has extensibility built in:

https://telegram.org/blog/bot-revolution

https://core.telegram.org/api

I just installed the Telegram app. Why is it asking for my phone number?

They use phone number as account name rather than email on mobile.

What if I don't want to use it on a phone?

The web and desktop versions can send an SMS to authenticate if you don't want to or can't use the phone app.

https://web.telegram.org/#/login

I see. I don't really want to tie it to a phone number, though.

Already did with the in-laws. :-)

Wasn't really a problem with ICQ, even though they had actively struggled and tried to change protocols frequently (and broke unofficial clients once in few months).

The community was large, and there was a significant demand for good clients (official one was shit). I guess now the difference must be that either official client is good enough for most users, or that users' attitude to how they want things had changed and they learned to submit to whatever service providers dictate.

So was AIM, though. That didn't stop the third party clients.

AOL worked actively to stop third-party AIM clients in the same ways as mentioned above from icq through WhatsApp -- changing protocols and central auth mechanisms.

http://www.cnn.com/TECH/computing/9909/06/aol.vsms.idg/index...

http://articles.latimes.com/1999/jul/24/business/fi-59086

Right, the point is "whatsapp is hostile to third-party clients" makes no sense as an explanation of why we don't have third-party clients for whatsapp, because all third-party clients for everything have had to deal with hostility from the first party.