3. The method of claim 1 wherein executing the body of the first tag includes tag processing child tags in the body before invoking the first function referenced by the first tag.
3. The method of claim 1 wherein executing the body of the first tag includes tag processing child tags in the body before invoking the first function referenced by the first tag. 4. The method of claim 3 wherein one or more of the child tags produce output, wherein the step of executing the first tag further includes using at least a portion of the output produced by the child tags.