We are pleased to announce 1.9 release of SumatraPDF, a small, fast, free PDF, CHM, DjVu, XPS, CBZ and CBR reader for Windows.

The most significant addition in this release is support for CHM documents. Sumatra is slowly getting support for more and more document formats.

Robert Prouse contributed support for touch gestures (available on Windows 7 or later, if you have the right hardware i.e. touch-enabled screen).

Audio and video files linked from PDF documents are now opened in an external media player.

We’ve also improved support for PDF transparency groups.