Short answer: Rich media means the PDF is interactive - it has video clips, audio clips, and 3D virtual reality images. If a still photo is worth a thousand words, then interactive video, audio, and 3D images you can spin must be worth a million words! Hence the term, rich media.

Long answer: Adobe PDF documents can contain video clips, audio clips, and 3D virtual reality images you can spin 360 degrees. A virtual reality image, for instance, is very powerful and useful. Imagine being able to look at all sides of a model or to look in all directions at a layout room or prototype scene.

We can also do interactive quizzes or a demo of a DCC sound loco where you press various buttons to play different sounds or even change settings to see their effect. This leaves traditional paper print publications in the dust!

We feel the PDF format has gotten something of a bad rap because print documents formatted with desktop publishing applications and later put to PDF are not designed for easy reading on a computer screen. The portait orientation, for example, makes reading a PDF page on-screen a real pain. You have to scroll around, zoom in, zoom out - it's all very annoying and burns extra mental energy as you attempt to read the document on screen. No wonder most people prefer to read offline on paper!

With Model Railroad Hobbyist (MRH), we've thrown out the old-school print PDF paradigm and started over. MRH uses many new online reading design concepts, and being able to add rich media content really leverages this format to its fullest. The fonts used, the "white" page background color, the way the writing is organized all need to be adjusted from the typical approach. The result is a PDF document that's a delightfully entertaining and educational experience.