Simplicity.

Our annotation language is small and simple. There are 15 keywords and a small number of simple concepts. The basic annotations require a knowledge of C and the library's data structures. The advanced annotations require a deeper knowledge of the library's implementation. Anecdotal evidence suggests that the language is intuitive. When shown the advanced annotations for PLAPACK, the head of the PLAPACK project claimed that they seemed ``very natural."

While our language is quite simple, we believe that we can simplify the use of the language. Eventually, we imagine that basic annotations will only be specified where static analysis fails. For example, a static analysis tool could guide the annotation by identifying routines that must be manually annotated.