As Joel points out, web applications run on servers, and even if they’re written (as many of them are) to run on Microsoft servers, they can also run “pretty well under Linux using Mono”, so not only do they make Microsoft’s dominance of the desktop redundant, they don’t even guarantee it can retain a presence on the server. What’s more, there are plenty of efforts currently under way to add rich-client functionality to the browser environment. This is a big, rapidly growing market that’s crying out for a next-generation client system, but Microsoft has shut down any work on developing a better browser, and is instead gambling all on persuading the market to wait for it to deliver its shiny, new, Avalon-based Windows technology.
The demise of Windows would be one hell of a sea change, but Joel’s essay is creating a lot of waves because he’s made a very strong case that it could happen. I think Avalon sounds a lot like microchannel, and that makes Longhorn equivalent to the PS/2: marvelously engineered, but destined to be late, unpopular and ultimately one of the biggest mistakes in its creator’s history.
Nevertheless IBM did recover from its microchannel episode, and even microchannel technology itself was ultimately assimilated into the PCI bus that remains at the heart of modern PC architecture.
In ten years time, when applications run in rich browser clients, Windows will have settled into its legacy platform niche, the much-derided Avalon will nevertheless have made important contributions to subsequent innovations, and Microsoft will be working hard to re-establish the market position of Office having relaunched it as a web-based application. The company will seem remarkably chastened compared to its standing today, but it will still be a force to be reckoned with.