Everything important is backed up on the usb stick. The application can be set up on XAMPP or any other webserver with it.

I'll actually be sending out emails if there are more than 14 consecutive backups on the usb stick to remind the customer to switch them ;)

I've written about the technical details somewhere here in the comments. Just search for "websocket", it should be in here…

The user accesses it with a small desktop application which finds the box in the same network by itself and opens open3A.

No, wasn't me. I actually decided against posting the link here.

Nope, I did not ;)

Actually I am, thank you! Having quite some fun now :D

I don't see that happening. They would have to offer support for the new product and most of my marketing is word of mouth nowadays. Should work out just fine ;)

Sometimes a client sends me some code to put in my version for future updates. But other than that, I don't work with contributions.

It's more the feeling for me, yes :)

I'm wondering, if someone sends me code to include in my project, how can I be sure they are the rightful copyright owners of that piece of code? Also what kind of legal liability it might put me in if I then publish that code as open source?

Yes, the extensions are AGPL also.

The management works like this:

Every open3ABox has an open websocket connection to my server. I do the monitoring over this connection and for updates and support I tell the box over the websocket connection to forward a port via ssh to my server. The port will be automatically closed by the open3ABox after three hours.

This means no constantly open port and an encrypted connection where only my server is allowed to do a remote function execution (get monitoring values, open port, etc.) on the box.

That is very clever, I like it. Especially dependency on proven and simple technology. VPN swarm like e.g. ZeroTier which I was thinking about would be too complex and thus harder to maintain.

Thank you for the explanation!

Nice.

Reverse ssh tunnels are a really good way to manage stuff like that.

Thanks :)