SkiaSharp is a cross-platform 2D graphics API for .NET platforms
Fileaxy does file sync, de-duplication, image matching & bulk preview
A cross-platform command-line tool to convert images into ascii art
A music downloader that understands your metadata needs
A Java gui for MP4Box
Hybrid visualization framework for desktops, large immersive displays
Simple Image Frame
FOSS Ebook Server, With no windowing requirements