ImageJ is an open source Java image processing program inspired by NIH Image.

It runs on any computer with a Java 1.8 or later virtual machine.

Downloadable distributions are available for Windows, Mac OS X and Linux.

ImageJ has a strong, established user base, with thousands of plugins and macros for performing a wide variety of tasks.

Fiji is a "batteries-included" distribution of ImageJ, bundling many plugins which facilitate scientific image analysis.