Sumatra PDF is a free PDF, eBook (ePub, Mobi), XPS, DjVu, CHM, Comic Book (CBZ and CBR) reader for Windows.
Sumatra PDF is small, portable and starts up very fast.
Simplicity of the user interface has a high priority.
Reference: http://blog.kowalczyk.info/software/sumatrapdf/free-pdf-reader.html
