Because processing has the same syntax as the document, only one set of editing tools is needed. Files that contain primarily processing instructions, for example tagsets and configuration files, are nevertheless perfectly valid documents and can be treated as such. This allows software and its documentation to stay together. Tagsets and configuration files can easily be turned into readable HTML or printed documentation. An important feature of the Input interface, however, is that the tree never has to exist in its complete form.
Processor defines the interface for the classes that actually process documents.
It also means that standard HTML authoring tools can be used to create documents. This is true even if the input format is HTML, so that the DPS is easily integrated into any XML-based system. The DPS works well with both. The PIA uses its own, extended implementation of the DOM as its internal representation, but because of the extensions it is not really suitable for use in other applications. However, any DOM implementation can be used as an input or output for the PIA, making the PIA suitable for use with other DOM-based software such as XML databases and document managers.