Okular - Okular is a universal document viewer based developed by KDE.
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
TwistedBrush Pro Studio - A powerful and unique natural media painting program.
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.
Corel Painter - Corel Painter is media painting software.