There are a few different flavors of ImageJ with very similar names, and some confusion is inevitable. Below is a table which should help to clarify the purpose of each. For the historical context of these projects, see History below.
|ImageJ developers||A new version of ImageJ targeting scientific multidimensional image data. It is a complete rewrite of ImageJ, but includes ImageJ1 with a compatibility layer, so that old-style plugins and macros can run the same as always. ImageJ2 provides several significant new features, such as an automatic updater, and improved scripting capabilities.||Dec. 2009||Active|
|ImageJ1||Wayne Rasband||A stable version of ImageJ which has been in development since 1997. It has a strong, established user base, with thousands of plugins and macros for performing a wide variety of tasks.||1997||Active|
ImageJA is a project that provides a clean Git history of ImageJ1, with a proper 'pom.xml' file so that it can be used with Maven without hassles.
It is what ImageJ2's legacy support uses at its core.
Fiji is Just ImageJ, with extras. It is a distribution of ImageJ with many plugins useful for image analysis in the life sciences. It is actively maintained, with updates released often.
As of June 2014, Fiji is based on ImageJ2, adding Fiji-specific customization and plugins.
We recommend Fiji as the preferred version of ImageJ.
|MBF ImageJ||Tony Collins||
It went hand in hand with a comprehensive manual describing how to use the bundle with light microscopy image data. It was a great resource by microscopists, for microscopists. Unfortunately, the manual went offline in late 2012. Nonetheless, it is often possible to add specific plugins from MBF ImageJ to a Fiji installation, combining the best of both programs.
|ImageJ2x||Rawak Software||ImageJ2x is a fork of ImageJ1, modified to use a Swing interface.||Unknown||Active|
|SalsaJ||EU-HOU||SalsaJ is a closed-source fork of ImageJ1 intended for use with professional astronomy images. It was designed to be used in classrooms, and has been localized into over 30 different languages.||Unknown||Last update:|
ImageJX was created as a means to discuss and explore improvements to ImageJ. There was an ImageJX mailing list as well as an ImageJX software prototype.
The ImageJX software prototype was a proof of concept—an attempt to reorganize ImageJ's internals to make it more flexible. The prototype demonstrated this flexibility by recasting the program in Swing. The ImageJX project formed the basis of an application to NIH for funding, which is what launched the ImageJ2 project (see above).
|Mar. 2009||Superceded by ImageJ2|
|NIH Image||Wayne Rasband||NIH Image is a public domain image processing and analysis program for the Macintosh. It is the direct predecessor of ImageJ, and is no longer under active development (though see ImageSXM below).||1993 or earlier||Superceded by ImageJ|
|ImageSXM||Steve Barrett||Image SXM is a version of NIH Image that has been extended to handle the loading, display and analysis of scanning microscope images.||May 1993||Active|
Here is a timeline of ImageJ development since its inception.
- Schneider, C. A.; Rasband, W. S. & Eliceiri, K. W. (2012), "NIH Image to ImageJ: 25 years of image analysis", Nature methods 9(7): 671-675, PMID 22930834, <http://www.nature.com/nmeth/journal/v9/n7/full/nmeth.2089.html>.
- Schindelin, J.; Rueden, C. T. & Hiner, M. C. et al. (2015), "The ImageJ ecosystem: An open platform for biomedical image analysis", Molecular Reproduction and Development, PMID 26153368, <http://onlinelibrary.wiley.com/doi/10.1002/mrd.22489/full>.