SciJava Common is a shared library for SciJava software. It provides a plugin framework, with an extensible mechanism for service discovery, backed by its own annotation processor, so that plugins can be loaded dynamically. It is used by downstream projects in the SciJava ecosystem, such as ImageJ and SCIFIO.

The legacy component enables backward compatibility with the original version of ImageJ (1.x). It contains the code necessary to translate between ImageJ and ImageJ2 images, so that ImageJ plugins can be executed faithfully.

This library contains ImageJ's core image data model, based on ImgLib2. It is the primary mechanism by which image data is managed internally by ImageJ2.

ImageJ Operations: a framework for reusable algorithms.

SciJava user interface components for Java Swing.

Core commands for ImageJ.

Keeps components of ImageJ up-to-date.

The executable which runs ImageJ. Its purpose is also to make sure that updates downloaded by the ImageJ Updater will be put into place before starting the Java Virtual Machine.