When a "proper document" is necessary, the ddPDF system provides a mechanism which can automatically render most standard business correspondence from an existing dataset. Like ddi, this framework is very "close to the metal"; new document templates must be hand-coded, but the resulting PDF generation requires no manual intervention and can be integrated with any existing data source. Originally developed as an "interesting experiment", the ddPDF system has been used (both with ddi and as a standalone utility) to generate property rental listings, invoices, and summary reports.
At the core of ddPDF is a library of hand-coded PostScript
page layout functions. The "top half" is a script which collects the
source data (from a database, or a web form, Excel spreadsheet, etc.)
and renders a complete PostScript
program which invokes primitives from the page layout library.
This program is then passed through a distiller to create PDF
output, which can be integrated as necessary (sent as an email,
added to a website, uploaded directly to a printer, etc).
An example document can be seen here.