Profiling XML Schema

XML Schema is now 5 years old, having matured from a newborn into an active youngster. So what have we learned about this young one's personality? We've always known it was complex. Indeed, the original debate about whether to make it a Recommendation indicated concern. (See Last Word and Questionnaire.) This rich toolset has caused schema designers to wonder which features they should or should not use. If we analyze what people are actually implementing, perhaps we can glean some guidance. I decided to embark on a quest to see if we can put together a profile of XML Schema based on experiences thus far.