To implement this design goal, the structure as set out below was developed. An example of a functional concept is interprocess communications. Another example is a graphics canvas. The library is layered, with packages residing wholly in a single layer. Each layer of the library may hold one or more packages.
Packages have no dependencies on other packages at the same or higher level.
Packages at higher levels of the library provide more power than packages providing similar functional concepts at lower levels. The interfaces to lower level packages are published so that the programmer can work at a more primitive level if the higher level packages do not provide the required functionality. All functions provided by a package are prefixed by the package name and an underscore character. An example of how this works is the core communications infrastructure, which spans four levels. Because of the recursive, hierarchical nature of the data structure, arbitrarily complex structures may be represented.