Comment by Telaneo

> - MDI applications, for example old Photoshop and old Excel, can have multiple child windows inside of a single window. If you close the main window with the X button then everything closes.

You can do the same on MacOS?

> - If you start multiple instances of an application you'll see multiple instances in the taskbar. On MacOS this is not really the intended way, you are supposed to have multiple windows. Afaik you can only launch multiple instances from the command line.

Are there any MacOS programs that don't allow you to have multiple windows of the app open, thus not giving you the equivalent experience? (cf. Firefox will let me have two browser windows open. I don't need two separate instances for it to act as though it were). I've never had this issue before, but that might just be me.

> On Windows there are apps that minimize to tray instead of closing. I'd say that this is a similar problem but its a bit better than Slack on MacOS that just minimizes to Dock when you click the X button.

There are apps like that on MacOS too. I don't think that's really the intended way to do things, and what Slack does sounds even worse than that, but that's a Slack problem, not a MacOS problem.