One of the big problems I've seen with multi-vendor systems that co-operate is if something didn't work. It was never clear where the problem was because the sy

One of the big problems I've seen with multi-vendor systems that co-operate is if something didn't work. It was never clear where the problem was because the system incorporated multiple products from multiple vendors. So if your resizer object didn't work for some images after upgrading Photoshop, but it used to in the old version, how do you get that fixed? In a single-vendor program, it's clearly a bug in the program and you can hand it back to the vendor to fix it. When multiple vendors are involved, it gets way more complicated. Each has a tendency to blame the other, and not take responsibility for the problem. Each will claim that they are coding to the interface specification. And they might be, it's just that the specification isn't tight enough to make all interactions bulletproof. I don't really have a solution (apart from "write a really, really, tight interface. No, tighter than that"), but I've seen the problem enough to be skeptical that we can have this. edit: I should add that I wish we could have this.