No to a), yes to b), mostly.

For all practical purposes, Edge is the next version of Internet Explorer. New features aren't being added to Internet Explorer 11, only to Edge. Yes, Edge has higher system requirements than Internet Explorer 11, but that's not relevant to my point. The same was true of Internet Explorer 9, which didn't run on Windows XP, but that didn't mean Internet Explorer 9 wasn't the next version along from Internet Explorer 8 or that it was "a completely different browser" or "a completely different product". It just means it's got higher system requirements, that's all.

The only thing the higher system requirements mean in practice is that the timetable for upgrading is delayed for some organisations. Those that aren't on Windows 10 will upgrade later than those that are. This means that it's not a blocker for using service workers, just a pretty typical delay while we wait for organisations to upgrade. As I keep saying, it's just an upgrade issue.

Saying that Microsoft aren't adding support for service workers to Internet Explorer while leaving out the massive fact that this is because Internet Explorer is the legacy version and they are adding it to the next version along, Edge, gives a radically different impression to what is actually happening. It implies that we'll never be able to use service workers because a major browser vendor isn't supporting it, when the reality is the opposite – that Microsoft are adding it to the next version of their browser and that all web developers have to do is wait for people to upgrade.

This is then compounded by the claim that Apple are doing the same thing – which is also untrue. Apple are adding service worker support to Safari right now, you can even go and look at the code yourself.

Yes, I understand that in terms of IT operations, the upgrade from Internet Explorer 11 to Edge is not without its complications. But it doesn't matter to the point I'm making. This is an upgrade issue, not a "multiple browser vendors have killed service workers" issue.

> If you're going to contend that a missing feature in one product is only an upgrade issue because you can change the entire OS and then install a completely different product to do the same job and then get that feature then I don't know what wouldn't be "just" an upgrade issue.

Changing from a previous version of Windows to Windows 10 is an upgrade. Changing from a previous version of Internet Explorer to Edge is an upgrade. It's quite clear why I'm calling this an upgrade issue, and I don't see how you can think that logic applies to things other than upgrades.

An example of what wouldn't be an upgrade issue is what I am explicitly contrasting against here. Two major browser vendors refusing to implement service workers wouldn't be an upgrade issue. If Microsoft and Apple won't add support for service workers to their browsers, then developers can't just wait for people to upgrade because newer versions won't include support either.

That's why it's so relevant to say "hang on, that's not right, both Microsoft and Apple are adding support to the latest versions of their browsers". It's the difference between service workers eventually being usable with a great deal of cross-browser support, and service workers being dead outside of small niches.