Sumatra PDF Portable is the lightweight Sumatra PDF viewer packaged as a portable app, so you can view PDFs on the go.
Sumatra PDF is a slim, free, open-source PDF viewer for Windows. Sumatra has a minimalistic design. Simplicity has a higher priority than a lot of features. Its small and starts up very fast.
What's New in version 0.9.1:
improved rendering of some PDFs
support for links inside PDF file
added -restrict and -title cmd-line options (contributed by Matthew Wilcoxson)
enabled SyncTex support which mistakenly disabled in 0.9
