STDU Viewer is a document viewer for multiple file formats. The goal of this software is to replace the multiple document viewers with a single simple application. STDU Viewer supports TXT, TIFF, PDF, DjVu, Comic Book Archive (CBR or CBZ), XPS documents format. This is most popular formats for scientific and technical documentation. Use content for quick jumping from one section to another. You can create your own named bookmarks for easy access to part of document. STDU Viewer free for non-commercial uses. Yes. You can use this program without any fees.