Jmol is a Free, Open Source molecule viewer and editor. It is a collaboratively developed visualization and measurement tool for chemical scientists. Jmol is an active project, and there are new features being added to it on a daily basis. Users are encouraged to modify it to fit their needs and to contribute their changes to the project.
JOELib/JOELib2 is a cheminformatics library which supports SMARTS substructure search, descriptor calculation, processing/filtering pipes, and conversion of different chemical file formats. It is written in 100% pure Java, and interfaces to external programs (e.g. Ghemical) are available.
ImageJ is an image processing program inspired by NIH Image for the Macintosh. It can display, edit, analyze, process, save, and print 8-bit, 16-bit, and 32-bit images. There are modules for biology, astronomy, nuclear medicine, physics, and more. If you can take a picture of something, whether with a microscope, a telescope, an oscilloscope, an xray machine, or a scanner, then this program will let you enhance, manipulate, and measure the results.
BioCoRE is a collaborative work environment for biomedical research, research management, and training. It features easy-to-use tools, among them co-authoring papers and other documents, running applications on supercomputers, sharing molecular visualization over the Internet, notifying project team members of recent project changes by email, chatting, keeping a lab book, and other practical features.