STDU Viewer is a file viewer for the most popular formats of technical and scientific documentation, such as TIFF, PDF, DjVu, XPS, JBIG2 and WWF formats.
In addition to these formats, it additionally supports FB2, TXT, Digital Comic Book Formats (CBR or CBZ), TCR, PalmDoc(PDB), MOBI, AZW, EPub, DCX and image (BMP, PCX, JPEG, GIF, PNG, WMF, EMF, PSD).
The software has an organized and friendly interface, being very easy to use. It has a number of features like exporting and converting files.