[tw04]

Serious question: why? I mean, maybe as a really, really lazy hack if you've got free azure credits and don't ever plan on actually supporting Azure in your codebase. But that seems like a very, very corner case. Would anyone ever actually do this for something production? Why wouldn't you just write native azure support, it's not THAT difficult.

[rsanders]

I probably use 20-30 apps that support using S3 that I can think of right now. Not all of them are maintained by me or even open source. Other than a proxy, it's impossible for me to change some of them.

In terms of use case: my company has a customer that requires us to locate an instance of our product in Azure, and some of that infrastructure is much easier to move with a compatibility layer.

You might as well ask why there are any standards in software and networking at all, as each new protocol or library isn't THAT difficult to support.

[LoungeFlyZ]

I'm guessing migration of existing apps/code could be quicker/cheaper. But as you say it shouldn't be that hard to port.