Amazon Kindle - Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and...
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
Google Play Books - Google Play Books lets you search, preview, and buy millions of books using Google Book Search.
calibre - Ebook manager, viewer & converter
Kindle Cloud Reader - Kindle Cloud Reader lets you read ebooks instantly in your web browser - no Kindle device required.
Okular - Okular is a universal document viewer based developed by KDE.