Sumatra PDF是一款免费开源的PDF阅读器,，它支持打开PDF、ePub、MOBI、XPS、DjVu、CHM、CBZ 和 CBR文件。优点在于简洁的界面，没有注释功能，没有导出TXT功能，功能极度精简，专注于PDF等文件的浏览阅读。可查看中文PDF，除了pgup/pgdn翻页外，还可用p/n (previous,netx)翻页。
更新日志：
http://sumatrapdfreader.org/news.html
2015.10.24 v3.1
* 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
安装版特性：
支持系统预览PDF格式、支持设置PDF默认阅读器、支持安装PDF浏览器插件到谷歌,火狐等
便携版特性：
不支持设置PDF 默认阅读器，其实可设置属性打开方式为默认、不支持系统预览PDF格式等
Sumatra PDF v3.1 正式版 安装版 + 便携版：
http://yunpan.cn/cFEj3UpS8LaGx 访问码 90fe