A cross-platform XML/CSS based eBook reader
CoolReader is fast and small cross-platform XML/CSS based eBook reader for desktops and handheld devices. Supported formats: FB2, TXT, RTF, DOC, TCR, HTML, EPUB, CHM, PDB, MOBI. Platforms: Win32, Linux, Android. Ported on some eInk based devices.
xCHM is a cross-platform GPL frontend for CHMLIB (http://www.jedrea.com/chmlib/) written with the wxWidgets framework.
Ultimate Webshots Converter is a Webshots pictures converter. It is able to show and save into JPEG files the pictures contained in the following files : WBC, WBZ, WB1 and WBD.
libdjvu is a DjVu Viewer for Hanlin V3 written in C. It has infinite levels of zoom in/out, window panning around the page, asynchronous page readahead, multicolumn mode and many other features.