Déjà vu -- The Graphics File Format
By now, most of us are familiar with PDF files as a way of sharing documents over the internet. PDF files can sometimes be large and take a long time to download. The DJVU (pronounced déjà vu) file format, while not as ubiquitous as PDF, provides excellent resolution of graphics/text and smaller file sizes. On one recent project, I prepared a file as a PDF and a DJVU file. The DJVU file was only about one third the size of the PDF and looked better! Why should I know about DJVU? Many archival materials that are made available over the internet use it for the reasons cited above.
On this website, the Gazetteer of Poland 1933 is furnished as DJVU files. Storage of its over 2000 pages is more economical than using PDF. I have also recently added a centennial booklet from Duncan, Nebraska in DJVU for download. The same is true of a program booklet of a fundraiser for the Polish Military Alliance of America. In all cases, a dialog will open asking where you would like to save the DJVU file.
But how do I view a DJVU file? One option is to find a plugin for your browser so you can see the page within your browser. I installed one for Chrome and while it worked I was disappointed that screen space was used for advertising. The second option is to find a standalone program (not part of the browser). I use DjVuLibre but there are others you might explore as well.