Web-based != run anywhere

Those people who claim that one of the great things about web-based services is that you can access them from any machine seem to overlook the fact that web-services just make a different trade-off; rather than being dependent on a particular operating system, they’re too often dependent on a particular browser.  At my company we have web apps that only run in Firefox and apps that only run in Explorer (6, mind you), which make it a little tough when you primarily use Safari.

Yes, the differences between browsers are arguably smaller than the differences between operating systems, so porting an app across browsers is usually less work.  But please, don’t try to pretend web apps are write once run anywhere.  Or if you do, please instead say that they’re just as write once run anywhere as Java.