TightVNC Java Viewer is available under the terms of the GNU GPL license.
You can browse the source code here:

  http://vnc-tight.svn.sourceforge.net/viewvc/vnc-tight/trunk/java/src/com/tightvnc/

TightVNC Java Viewer uses JSch for SSH connectivity:

  http://www.jcraft.com/jsch/

For JSch licensing terms, see the LICENSE-jsch.txt file.
