JChemPaint (or JCP for short here) is the editor and viewer for 2D chemical structures developed using CDK. It is implemented in several forms: a Java application and two varieties of Java applet.
Please see the documentation at https://github.com/JChemPaint/jchempaint/wiki for more information.
The issue tracker here (on top of this page) is for specific JCP-related bugs. For problems in CDK proper, please use http://sourceforge.net/tracker/?group_id=20024&atid=120024