Exceptions

Checked or not?

Not everyone likes the convention of making everything a RuntimeException!

Rendering

Rendering exceptions using templets does seem to be the way to go, especially since it provides a solution in principle to the problem of supporting different locales/markup languages.

Context information

The mechanism for attaching contextual information to exceptions as they find their way up the stack has some disadvantages: we are wrapping the original exception in a "more general one" as it comes past. Although this does provide an obvious place to attach context info, it does make it harder to net the original exception in a catch clause.

It might be better to attach context info explicitly in a Stack of ExceptionContexts. These could have their own templets.