The browser is dual licensed under the GNU Public License and a commercial license from Practical Thought. Some older code derived from code under BSD license. Note that the browser uses the library, below.
The command-line document manipulation tools in tool.* package and subpackages are free for use on the command line. Practical Thought licenses versions with more features and with programmatic interfaces. library
Software in the package and subpackages (including the font engine and new I/O) has been generously licensed by Practical Thought for by the Multivalent project for non-commercial uses. It can also be licensed for commercial use.
Font metrics for Adobe PDF core fonts derived from Adobe Font Metrics files under license. PDF and PostScript operators and data structures copyright Adobe Systems Inc. CMap files copyright Adobe Systems Incorporated.
BZip2 used under Apache Software License.
Some icons from AIcons and the Java Look and Feel Repository.