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.
The edit-on JavaBean SDK is a customizable, feature-rich JavaBean that allows developers to add WYSIWYG editing functionality to their AWT- or Swing-based applications. It features an intuitive word processor-like user interface that enables XHTML content authoring with XML markup, and has a royalty free run-time license.