Simple image comparison tool
3DimViewer is a lightweight 3D viewer of medical DICOM datasets.
nomacs is a fast and small image viewer
Simple and intuitive 2D vector drawing for electronics and not only.
Former project page
Free projection software for churches
JavaScript-Based Molecular Viewer From Jmol
Interactive designer for Celtic knots
Superseded by the official Gimp release: http://www.gimp.org/downloads
a screenshot and annotation tool
Real-time 3D viewer for LDraw LEGO models with OpenGL acceleration.
A free and open source screenshot tool optimized for productivity