What are some alternatives?
When comparing Document Viewer and Amazon Kindle, you can also consider the following products
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
FBReader - FBReader is an e-book reader for various platforms. Features:
Okular - Okular is a universal document viewer based developed by KDE.
calibre - Ebook manager, viewer & converter
Cool Reader - Fast and small cross-platform eBook reader for desktops and handheld devices
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.