JMicroVision - Image analysis toolbox: measuring and quantifying components of high-definition images
Fiji - Fiji: A batteries-included distribution of ImageJ.
ImageJ - and Other Health Care
Icy - Icy is an open community platform for bioimage informatics
MIPAR - MIPAR is a revolutionary image analysis software, capable of identifying and measuring features...
Paint.NET - Paint.NET is a free image and photo editing software.