Graphics - working in Liunx the best way to get "what you print is what you see" is to create a PDF and then print it with scaling off. Programs such as LibreOffice and Inkscape printer drivers have not been all that reliable to print properly, but export to PDF and print overcomes that.<p>Web Reporting - for web apps creating address label sheets with formatting that "just works" also is best route via PDF. Secondly is using tools such as PHP's FPDF/FPDI you can use PHP to programmatically fill out PDF forms, used that a lot for report forms like the DE542.<p>The main benefit of PDFs is that the PDF document accurately represents what you create across platforms (by including fonts, etc.) So it is very important for presentation documents, reports, and press-ready publication.
Visualizations, e.g. I have a script that composes a huge image from road traffic video which you can see at different scales. In raster it would be something like 200 MPx for desired level of detail, whereas in PDF you can freely mix raster and vector graphics in portable way.<p>Also, scanned document compression, using Mixed Raster Content technology.