Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.
Okular - Okular is a universal document viewer based developed by KDE.
Xodo - Try easy-to-use PDF tools that keep your documents safe. Work with your important files across all platforms and devices with the ultimate all-in-one document solution. Your productivity lives at Xodo!
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
PDF Expert - Download a free trial of PDF Expert - the best PDF software for your Mac. Enjoy advanced reading layouts, powerful PDF editing and classical annotation tools.
Atril - Atril is a simple multi-page document viewer. Atril is a fork of Evince.