A great article! There's a few ways to distribute an app to Macs outside the app store, but if you're writing cross platform software then Conveyor [1] can be a helpful tool especially if you're new to desktop development. It can build, sign and notarize Mac apps from Linux or Windows + it understands Electron and JVM apps natively so if you use those the whole release process can be done from your dev laptop. We're adding Flutter next but Flutter apps require compilation on each target OS so you'd need to use a Mac or have Mac CI access in order to build the executables.

A few misc thoughts:

1. Sparkle is a great update engine, Zorg is a very skilled and hard working developer. Conveyor integrates it into your app without needing any code changes so you can use it even if you aren't an Objective-C/Swift dev.

2. Skipping notarization. Conveyor can generate self signed apps along with a download.html page that tells users what to do, if you don't give it signing keys. The page repeats Apple's instructions for bypassing Gatekeeper via the UI (right click+open), and it also supplies a `curl|bash` script that does the same thing. It's free for open source apps and we have some users who use it to distribute self-signed apps via GitHub Releases with updates. You can also distribute CLI apps this way (without homebrew) but that feature isn't quite finished/documented yet, it's sort of pending launch until we understand how much demand there actually is.

I personally think notarization is a reasonable balance that works better than the approaches taken by Windows and Linux, but there are cases where it's just getting in the way. One obvious case is internal tools that you're distributing to colleagues - in this situation personal developer ID might not be appropriate but the company may guard its actual signing keys with complex process. In those cases you already know the source of the app and don't need Apple's help staying safe. Self-signing (rather than being entirely unsigned) makes Apple Silicon Macs happy, and allows the OS to remember what permissions the app has across upgrades.

3. You don't need code signing certs for sign web apps (just TLS certs) because of the sandbox. I'm exploring the possibility of a new feature - signing using our keys for people/projects that can live inside an app sandbox. You'd upload the output of your build system and we'd then build, sign and host the resulting packages. If you control the packaging you control the entry point which means you can then drop arbitrary privileges before executing the real code, and it means you can force updates to occur if sandbox holes are found. The problem is that you're competing against the price of just buying keys, so it's a bit unclear how much demand there is from the non-open source users who would ultimately be paying for it.

4. Desktop distribution can be a somewhat mysterious/difficult topic for people new to it, especially all the signing stuff. Conveyor isn't open source for better or worse, but the flip side is that it comes with commercial support. In the past we've been able to help customers even with bugs in third party libraries that only showed up when an app was packaged, and only on macOS.

[1] https://hydraulic.software/ (disclosure notice: I wrote it and run the company)