Sumatra PDF is a free PDF, eBook (MOBI), XPS, DjVu, CHM, Comic Book (CBZ and CBR) reader for Windows. Sumatra PDF is small and starts up very fast. Simplicity of the user interface has a high priority. Portable version included (a single executable that can be run e.g. from USB drive and doesn't write to registry).
What's new in Sumatra PDF version 3.1:
- 64bit builds
- all documents are restored at startup if a window with multiple tabs is closed (or if closing happened through File -> Exit); this can be disabled through the RestoreSession advanced setting
- printing happens (again) always as image which leads to more reliable results at the cost of requiring more printer memory; the "Print as Image" advanced printing option has been removed
- scrolling with touchpad (e.g. on Surface Pro) now works
- many crash and other bug fixes