Imagej2-icon.png The current version of ImageJ focuses on analysis of scientific multidimensional image data. ImageJ2 includes ImageJ1 (see right) with a compatibility layer, so that old-style plugins and macros continue to work.

For users: ImageJ2 is a supercharged version of ImageJ1 with new features.

For developers: ImageJ2 is an entirely redesigned, more powerful set of software libraries.

ImageJ 1.x, sometimes shortened to ImageJ1 or IJ1, is the stable version of ImageJ developed by Wayne Rasband at NIH since 1997.

ImageJ grew organically over time as Wayne Rasband continuously added features according to user requests. Now there are thousands of plugins written by members of a diverse community.

Fiji-icon.png Fiji Is Just ImageJ—a "batteries-included" distribution of ImageJ which includes many useful plugins contributed by the community.

The Fiji distribution is built on the ImageJ2 platform.