6.9 SumatraPDF Document Viewer
SumatraPDF is an open source PDF reader for Microsoft Windows. The program also opens Open XML Paper Specification, DjVu, EPUB, XPS, FB2, CHM, CB7 CBR CBT CBZ, MOBI and PRC files.
Sumatra has a minimalistic design, with its simplicity attained at the expense of extensive features. For rendering PDFs it uses the MuPDF library. Sumatra was designed for portable use, as it consists of one single file with no external dependencies, making it usable from an external USB drive.
When re-opening a document, the rotation, zoom, window size, page, etc. are remembered from the last time that document was opened, making it behave more like an e-book reader than some other PDF viewers.
Sumatra does not lock the PDF file. Without closing the PDF file, a user can save over the PDF and then press the R key to refresh the PDF document. For example, a user could find this feature useful when, after recompiling the altered TeX source code, simply pressing 'R' and view the altered document.