Eve Reader is an open-source EPUB reader for Windows and Linux. Its interface is very easy to use. The fastest way to load the book in this is to drag and drop an eBook into the GUI. Although, open dialog box of this application shows that it supports “all files”, but this does not support nother file formats like Mobi or PDF. This support only EPUB.
Eve Reader is an Electron app, which means that it is huge and uses a lot of memory, and the file type support is limited to the EPUB format. It is available for Linux and Windows, thought not portable software.