There's a lot of FUD in this comments section, so I'd like to clear the air. I'm pretty big on OSS myself, so it pains me to see a company doing all the right things get lambasted like this.

Beeper is just a Matrix server running in tandem with a series of custom, open source bridges written by Beeper. The value proposition is not having to deploy a Matrix server yourself, and not having to deploy each bridge yourself.

However, if you want to do that you absolutely can. I've been running Synapse + a subset of their bridges for a couple years now (the WhatsApp one being the oldest), and they are fantastic.

The devs contribute back to Matrix all the time and are great about supporting the spec as a responsible third party.

Their only closed source software is their client, which is - by definition - only written to work with their servers and not generic Matrix servers (e.g. It's just a preconfigured matrix client which expects each bridge to be deployed, and doesn't ask you for things like what server you want). As a result, you wouldn't want to use it with your own stack; you can just pick one of the myriad OSS clients available for Matrix and go with that. I use SchildiChat, for example.

I don't understand why, after doing all this work and publishing the source online for free (free as in freedom), they aren't allowed to offer a preconfigured service to non tech savvy folk?

Honest question: Shouldn't they be paid for their work?

Edit: And, please, stop asking questions like "How do they connect to X/Y/Z, anyway?" - just go read the source and see for yourself. These are the good guys working completely in the open, and you're treating them as if Twitter just wrote a chat app.